# Ariens AX 414 main jet replacement



## Town (Jan 31, 2015)

The stock main jet works perfectly on the stock engine even at 3,700 rpm. And when you increase the rpm to 3,900 rpm and install a 6 blade impeller and increase the engine auger pulley from 2.75" to 3.25" the stock main jet seems to work fine too. The spark plugs seem to tell another story. The plug shows a nice brown colour in stock form, but after the changes to rpm and auger/impeller loading the spark plug is noticeably leaner. Left plug is stock and right is after changes.














I sought help on main jets from the Honda guys and @tabora and @drmerdp provided all the help I needed. Since the jet is normally a venturi design drilling out the jet is not recommended since it would destroy the venturi if drilled more that a thou" or so. A Honda clone jet or Honda jet for the 390 may well fit. I have no way of measuring the jet size, so I chose 1.13 mm as the stock jet size based upon an earlier posting. So I ordered two Honda 390 jets, a 1.15 mm and a 1.18 mm. Here is what the package for the 1.18 mm jet looks like including the part number:








So received the part from: Jet, Main, GX Series, Genuine Honda, GX120 thru GX390 series. today. The 1.15 mm jet appears to be the same size as the stock AX 414 main jet based upon a round tooth pick forced into the jets and measured with a digital caliper. The 1.18 mm jet is a little larger, so that got installed today.

Now wait until the fall to see what effect it will have.


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## foggysail (Feb 21, 2015)

No expert on plugs but IMHO the plug on the right has the conditions I would want rather than carboned up as shown on the left. Get enough carbon on the thing it will short out.


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## CarlB (Jan 2, 2011)

the one on the right might be a little hot but its not lean


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## dman2 (Sep 22, 2019)

A little lean is better than a little rich in my opinion, as it won't carbon build up as much and pollute the environment. I drilled out my fuel jet and it got rich quickly, which caused the engine to lost power and fouled the spark plug in no time.
I put the stock fuel jet back in and it is running like a king.

It is mainly Honda engines that benefits from larger fuel, jet.

You run your engine at higher rpm and it works harder, so of course engine temperature would be higher. Doesn't mean it is running lean I think. Different spark plug designs might yield slightly different results as well.

I see you like to have fun messing around. I'm somewhat like that.


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## Town (Jan 31, 2015)

@CarlB and @foggysail thanks for your comments. I just checked a number of plug colour reference guides. There are indeed a lot of very different interpretations of what to look for, especially due to the lean burn engines with fuel injection and computer regulated and feedback controls. The sites that dealt with plug colour from older design carb engines related the ideal colour as tan to brown on the ground electrode and grey as a lean condition. So I am pleased with the brown colour and not so pleased with the grey colour from the higher rpm and more loaded engine plug. 

@dman2 I do like upgrading my snowblower to make it work better for me. I would prefer slightly rich over slightly lean. So a slight increase in main jet size should not be a problem, but it will be a while to see for myself what works better. I have tried the choking test many times this year. One click of the choke makes no noticeable difference under any condition. Two clicks of the choke under load drops the rpm significantly and if I cannot react quickly enough to turn off choke the engine will stall. Drilling out the main jet is not supposed to be a good idea since the venturi effect is lost and the fuel is not atomized correctly and results in spitting fuel. I never realized the main jet had a venturi effect until the Honda guys educated me. Now with the jets in hand it is easy to see the venturi. The engineering is way beyond my skill level but @tabora and @drmerdp have it all sorted out and share their knowledge.


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## CarlB (Jan 2, 2011)

I think if you lower the temp range on notch it will be about ideal. I would not richen it up any.


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## Town (Jan 31, 2015)

CarlB said:


> I think if you lower the temp range on notch it will be about ideal. I would not richen it up any.


The plug on the left is the NGK BPR6ES and the one on the right is the Champion RN9YC which are both recommended for my engine as a replacement for the stock Torch plug. So they are both the same heat range. A one notch colder heat range for the Champion would be the RN8YC and for the NGK the BPR7ES, but the NGK is colder than the Champion. The heat range is finer for the Champion so the equivalent Champion to the NGK is RN7YC. My dealer has the NGK in stock and probably the 2 Champion heat ranges too, so I have your suggestion as an option if the richer main jet does not deliver on my expectations.


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## 1132le (Feb 23, 2017)

installed .46 117 jet today thinking about bumping rpm up another 100 t0 3940
my gasket was also not in place right i had small smell when gas left on hope its fixed now i need a new one
there 2 nubs on the gasket that should be in a certain spot


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## Town (Jan 31, 2015)

1132le said:


> installed .46 117 jet today thinking about bumping rpm up another 100 t0 3940
> my gasket was also not in place right i had small smell when gas left on hope its fixed now i need a new one
> there 2 nubs on the gasket that should be in a certain spot


My fuel bowl rubber o ring shrunk when i removed it. I expanded it on 1.5” ABS fitting and it fit perfectly and no leaking or smell since running the engine in late September. I did not see any nubs on the o ring.

I ran the engine on Sept 25th at 15C and it started as normal and operated at full throttle just like in the winter. So all good so far. No problems with my engine running at 3,900 or 3,950 rpm. Idle is lowered to 2,100 rpm now.


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## legarem (Sep 9, 2017)

With my AX414, when I lower the throttle from full to idle, there's a loud back fire each time I do that before shutting off the motor. Lean condition ? Plug reading seems ok.


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## 1132le (Feb 23, 2017)

could be other reasons for that it stinks its not fully adjustable


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## JLawrence08648 (Jan 15, 2017)

legarem said:


> With my AX414, when I lower the throttle from full to idle, there's a loud back fire each time I do that before shutting off the motor. Lean condition ? Plug reading seems ok.


Try slowly lowering the throttle especially from high to medium.


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## 1132le (Feb 23, 2017)

JLawrence08648 said:


> Try slowly lowering the throttle especially from high to medium.


cant its idle or full throttle i wish i could go to mid 1st i just close the fuel valve on full throttle let it run out


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## Mountain Man (Oct 14, 2018)

Was taught you always wanted the spark plug to be cardboard brown after running.


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## ChrisJ (Nov 27, 2014)

Why would increasing the rpm have any effect on what size jet you need?

I've never heard of this before.


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## Mountain Man (Oct 14, 2018)

Just a WAG here, but possibly with machines jetted so lean these days, after 3600 maybe the tiny jet cant supply any more fuel, but flows more air, hence leaning out the mix too much.


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## jherbicide (Oct 14, 2021)

ChrisJ said:


> Why would increasing the rpm have any effect on what size jet you need?
> 
> I've never heard of this before.


Whenever you change something, jetting ‘may’ also need to (or should) change.

I learned carbs tuning motorcycles, so a lot of the following doesn’t typically factor with these engines, but beat with me…

On bikes jets normally needed changed to a bigger size whenever an air box was changed to pods, baffles taken out of pipes, cams changed, etc. All of these factors change either how much air flows through the carbs, and/or “how” it flows (often referred to as the “signal,” or technically the actual pressure drop or vacuum pulse). Some mods don’t really increase flow, like subtracting an air box and putting on pods, but it does change (weaken) the “signal.”

On a fixed* speed engine like these, changing the rpm set point (governor) both increases the airflow and the “signal.” Sometimes it’s not enough to matter, or the signal changes in a manner to compensate for the airflow increase. Other times to get a proper mixture you need a bigger jet.

Generally speaking, bigger jets are required for more airflow (more rpm or more power)


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## Auger1 (Dec 4, 2020)

Why would you need a 6 blade impeller when the auger mod on a 3 blade will get the job done better IMO.


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## CarlB (Jan 2, 2011)

ChrisJ said:


> Why would increasing the rpm have any effect on what size jet you need?
> 
> I've never heard of this before.


the higher the rpm the more fuel is needed. if the jet too small it wont be able to flow enough fuel.


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## Town (Jan 31, 2015)

Auger1 said:


> Why would you need a 6 blade impeller when the auger mod on a 3 blade will get the job done better IMO.


The 6 blade impeller is larger than the current 3 blade. Slightly larger diameter and wider blades. The 6 blade moves more snow than the 3 blade. This is based upon measurement and subjective assessment by me and the complaints of neighbors.

What I don't like about the impeller mod is the restriction created by the rubber pad. My 6 blade has over 5" of blade depth from tip to the sloped back edge near the center. The painted surface has been polished down to the shiny metal. So I think the entire blade width and depth is necessary to flow more snow. The small pad at the tip is a restriction to full flow even if the elimination of a gap at the tip helps clear snow from impeller housing. Just my view of the different approaches.


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## Town (Jan 31, 2015)

Mountain Man said:


> Was taught you always wanted the spark plug to be cardboard brown after running.


Yes that is what I was taught too for carbs. The caveat is that brown is the efficient setting. For more power the mixture reading on the plug can be much darker. My plugs at the 3,900 rpm operating speed are much lighter than the ideal brown.


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## ChrisJ (Nov 27, 2014)

Town said:


> Yes that is what I was taught too for carbs. The caveat is that brown is the efficient setting. For more power the mixture reading on the plug can be much darker. My plugs at the 3,900 rpm operating speed are much lighter than the ideal brown.


As far as my understanding a leaner "correct" mixture produces more power assuming the extra heat doesn't cause preignition or destroy parts of the engine. 14.7:1 in a perfect world should yield the most power with gasoline and the hottest combustion.

One of the things a high performance tune does on a car engine is lean the mixture out at WOT as the stock setting is on the safer richer side.


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## Town (Jan 31, 2015)

ChrisJ said:


> As far as my understanding a leaner "correct" mixture produces more power assuming the extra heat doesn't cause preignition or destroy parts of the engine. 14.7:1 in a perfect world should yield the most power with gasoline and the hottest combustion.
> 
> One of the things a high performance tune does on a car engine is lean the mixture out at WOT as the stock setting is on the safer richer side.


Are you thinking of EFI on car engines? I don't think that applies to carbs on snowblower engines. Carbs operate on richer fuel mixtures because the fuel droplets are much larger then EFI and do not mix as well in the air stream.


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## legarem (Sep 9, 2017)

Best air fuel ratio with gasoline engines for maximum power is near 13:1. I installed a little computer on my previous BMW motorcycle so I could adjust AFR as I want by tricking the oxygen sensor . Stock AFR was 14,7:1 . When I adjusted it to 13:1, the motor was more alive but exhaust fumes were smelling bad.


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## ChrisJ (Nov 27, 2014)

legarem said:


> Best air fuel ratio with gasoline engines for maximum power is near 13:1. I installed a little computer on my previous BMW motorcycle so I could adjust AFR as I want by tricking the oxygen sensor . Stock AFR was 14,7:1 . When I adjusted it to 13:1, the motor was more alive but exhaust fumes were smelling bad.


Was that injected or carburated?


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## legarem (Sep 9, 2017)

Injected. Best AFR ratio for best power doesn't change if the motor has injection or it has is a carburetor.


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## ChrisJ (Nov 27, 2014)

legarem said:


> Injected. Best AFR ratio for best power doesn't change if the motor has injection or it has is a carburetor.


That's what I thought to be honest.
But I am surprised you saw better performance from 13.1 than with 14.7.

I think my last car ran 13.5:1 100% stock according to my ultragauge and I was always told by guys that tuned them that they leaned it up a little for more power. That was turbocharged, 16 psi stock, most aftermarket guys were running 23 psi.

I think I'm going to need to go back and ask a few friends in case my memory is wrong which sadly, happens a lot anymore.


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## ChrisJ (Nov 27, 2014)

So,
It appears I'm remembering wrong.
Guys typically run 12:1 even 11.5:1 in turbocharged cars for most power.


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## jherbicide (Oct 14, 2021)

ChrisJ said:


> So,
> It appears I'm remembering wrong.
> Guys typically run 12:1 even 11.5:1 in turbocharged cars for most power.


14.7:1 is theoretical, as in 100% of the fuel is atomized equivalently over the air mixture. In practice engines need a little more (as shown) to not have “dead spots” in the mix.


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## ChrisJ (Nov 27, 2014)

jherbicide said:


> 14.7:1 is theoretical, as in 100% of the fuel is atomized equivalently over the air mixture. In practice engines need a little more (as shown) to not have “dead spots” in the mix.



And then there's dealing with the imperfections of the carburetor.
Time and time again I tried to slowly lean out the main jet on my HMSK80 because I was tired of smelling it and my clothes stinking, but every time I tried it would end up hesitating during load changes. I blame that on the carburetor but I honestly don't know why, or how to make a better one.

I do feel Honda engines and Honda clones seem to handle this far better tho.


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## jherbicide (Oct 14, 2021)

ChrisJ said:


> And then there's dealing with the imperfections of the carburetor.
> Time and time again I tried to slowly lean out the main jet on my HMSK80 because I was tired of smelling it and my clothes stinking, but every time I tried it would end up hesitating during load changes. I blame that on the carburetor but I honestly don't know why, or how to make a better one.
> 
> I do feel Honda engines and Honda clones seem to handle this far better tho.


A big part that it is OHV vs side valve. Another big part is the intake/carb path the fuel/air mixture takes to go from carb to cylinder.

The Honda has a very short and straight path. The Tecumseh has a few hard direction changes. These cause the mixture to speed up/slow down. Every time the mixture slows down, it causes the fuel to ‘separate’ from the air and form bigger particles. These particles don’t atomize as well, therefore you need more fuel to make up for it.

Those are two main reasons side valve engines have been “EPA’d” the way of the dodo.


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## Town (Jan 31, 2015)

We had 7" (measured in my driveway) of fine heavy wet snow overnight and then some light rain. The EOD was wide and to the top of my bucket. The 118mm main jet (instead of the 114mm stock one) lowered the engine speed from 3,900 to about 3,870 rpm but it ran well, no smoke or smell or any other unwanted side effects. Conditions were unusual and I could not tell if it made more power, but not less power anyway. The engine seemed to cope better with the reduced rpm caused by overloading. So overall the bigger jet seems to be a keeper for now.


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## ChrisJ (Nov 27, 2014)

Town said:


> We had 7" (measured in my driveway) of fine heavy wet snow overnight and then some light rain. The EOD was wide and to the top of my bucket. The 118mm main jet (instead of the 114mm stock one) lowered the engine speed from 3,900 to about 3,870 rpm but it ran well, no smoke or smell or any other unwanted side effects. Conditions were unusual and I could not tell if it made more power, but not less power anyway. The engine seemed to cope better with the reduced rpm caused by overloading. So overall the bigger jet seems to be a keeper for now.


118mm?!?!
What are you feeding with that jet, a 20,000HP engine? 

Those damn decimals.....


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## Town (Jan 31, 2015)

ChrisJ said:


> 118mm?!?!
> What are you feeding with that jet, a 20,000HP engine?
> 
> Those damn decimals.....


The jet is a 118 and the diameter of the orifice is 1.18mm. Sorry for my mistake causing confusion.


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## harry398 (Jun 22, 2021)

Town said:


> We had 7" (measured in my driveway) of fine heavy wet snow overnight and then some light rain. The EOD was wide and to the top of my bucket. The 118mm main jet (instead of the 114mm stock one) lowered the engine speed from 3,900 to about 3,870 rpm but it ran well, no smoke or smell or any other unwanted side effects. Conditions were unusual and I could not tell if it made more power, but not less power anyway. The engine seemed to cope better with the reduced rpm caused by overloading. So overall the bigger jet seems to be a keeper for now.


interesting on the rpm loss...... I think ambient conditions will affect that...

I swapped back to the 102 in my 306ax engine...and did not recover the lost 100 rpm.( I also now remember I put 93 octane in it---which would also change from the 87 it had before) .and Now I hear it have a slight surge at full rpm NO LOAD with the original jet.... I still get 3750, and for now..thats plenty till i LOAD that engine hard. Really...its the only way to properly tune the engine....no load gives false signals.


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## ChrisJ (Nov 27, 2014)

harry398 said:


> interesting on the rpm loss...... I think ambient conditions will affect that...
> 
> I swapped back to the 102 in my 306ax engine...and did not recover the lost 100 rpm.( I also now remember I put 93 octane in it---which would also change from the 87 it had before) .and Now I hear it have a slight surge at full rpm NO LOAD with the original jet.... I still get 3750, and for now..thats plenty till i LOAD that engine hard. Really...its the only way to properly tune the engine....no load gives false signals.


I've wished I could not only have an adjustable main jet, but one with a cable that I can adjust from the handlebars while snowblowing.

No one makes such a beast unfortunately and even the adjustable jet I bought leaks due to bad design so I gave up on that too.


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## harry398 (Jun 22, 2021)

ChrisJ said:


> I've wished I could not only have an adjustable main jet, but one with a cable that I can adjust from the handlebars while snowblowing.
> 
> No one makes such a beast unfortunately and even the adjustable jet I bought leaks due to bad design so I gave up on that too.


not a fan of adj jets.

best design is what they have..screw in. trial and error..just like a race car. small baby steps


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## ChrisJ (Nov 27, 2014)

harry398 said:


> not a fan of adj jets.
> 
> best design is what they have..screw in. trial and error..just like a race car. small baby steps


Curious why you're not a fan of them?


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## Town (Jan 31, 2015)

My engine rpm has continued to drop and was down to 3,830 or so but quite variable. Decided to go back to stock main jet. Unfortunately the plastic clip holding the governor rod to the carb throttle assembly broke, allowing the small spring that is also attached to the throttle plate to fully open and the engine over speeded (turned engine off quickly) to about 4,700 rpm and caused the governor counter weights to exit their housing. So engine no longer has an effective governor. Totally my fault for removing the plastic retainer in the cold and breaking 2 of the 4 plastic blades holding it. 
Took off front plate of engine to confirm problem. Likely more damage so engine is toast. A LCT 414cc engine is $900 plus taxes and is on backorder, no used engines available. So a new Ariens 926084 Professional 28" is in my near future.

Looking at a Princess Auto 420cc engine to fix it and give to my son.


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## NOS (Dec 3, 2021)

ChrisJ said:


> I've wished I could not only have an adjustable main jet


Here you go








Adjustable Main Jet Kit for GX390/420 Gas Carburetors - EC Carburetors






www.eccarburetors.com


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## NOS (Dec 3, 2021)

Town said:


> My engine rpm has continued to drop and was down to 3,830 or so but quite variable. Decided to go back to stock main jet. Unfortunately the plastic clip holding the governor rod to the carb throttle assembly broke, allowing the small spring that is also attached to the throttle plate to fully open and the engine over speeded (turned engine off quickly) to about 4,700 rpm and caused the governor counter weights to exit their housing. So engine no longer has an effective governor. Totally my fault for removing the plastic retainer in the cold and breaking 2 of the 4 plastic blades holding it.
> Took off front plate of engine to confirm problem. Likely more damage so engine is toast. A LCT 414cc engine is $900 plus taxes and is on backorder, no used engines available. So a new Ariens 926084 Professional 28" is in my near future.
> 
> Looking at a Princess Auto 420cc engine to fix it and give to my son.


Post a picture of what you need and maybe I have parts.

If you want another engine price a long block kit on Amazon.ca


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## ChrisJ (Nov 27, 2014)

NOS said:


> Here you go
> 
> 
> 
> ...


That looks like it doesn't have the issue the one I bought does.


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## ChrisJ (Nov 27, 2014)

@Town I've been changing the jet on my 420n without pulling the carb. I just drop the bowl.


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## NOS (Dec 3, 2021)

With that kit you can do it in place for the high side but you will to remove if for the low side.

Off the top of my head I can't remember what jets to use in a 390. 
But I know your going to need even more on a 420.

Also not all clone carbs are the same some jet kits do not work.
There are two slightly different main jets and I can't tell you what you need.

Going back to the first photo I can't look at that plug and make a call.
I don't know how long it ran how much load ect.

I would suggest putting a timing light on the engine and verify its correct at full rpm or what ever its going to run at.
Cone ignitions tend to retard as rpm increase and Chinese tollerences are all over sometimes this extends to timing ( usually retarded )


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## ChrisJ (Nov 27, 2014)

You do have to be careful dropping the bowl though.


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## NOS (Dec 3, 2021)

My shop is a mess so I usually do carb work on soft rubber mat on the kitchen table.
Too easy to lose things....

Boy its a slippery slope when you have an idea what you want and how to get there.

My first reaction is always to reach into the race parts bin and see if there is an easier to tune solution.

EC Birt's Adjustable jet is a very good carb upgrade.

And I would be inclined to swap out that dumb clone ignition for a newer CDI unit from Honda.
Part number 30500-Z5K-801
Its a pretty good ignition you will have to manually set up but its easier starting and has a modest advance curve for the higher end operation.

You have to make one change at a time and test that.
For what you have in the very first photo on this thread the one plug looks a little cool and the other looks a little hot but there are so many variables its pointless to say much.
Maybe... Maybe try a 7 instead of a 6.
Looking at the ground strap tells me how the heat is moving through it and I can guess a few things about timing.
What ever the RPM range it was at the timing looks OK

Still its nice to put a timing light on these things and see what you have VS what you are supposed to have 25 Btdc.
If you don't have that then you need to correct with an offset key.
Then you play with the carb and put it under a load at the RPM you want and work it.
Then shut it down and pull the plug ( no idle ).

That way you have a clear idea what is going on when you read the plug.
Everything else is guessing.


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## Town (Jan 31, 2015)

ChrisJ said:


> @Town I've been changing the jet on my 420n without pulling the carb. I just drop the bowl.


Yes I agree it is easy to do that way except for the rectangular sealing rubber "gasket" on my engine. The rubber gasket will not stay in alignment for me. Bought a new gasket in a kit and same problem. Turning the carb upside down is the only way that I can get the alignment correct so no leaks. The gasket should fit snugly in its groove but doesn't. There are little nubs on the side of the gasket but they don't improve the fit. I don't like using gasket adhesive products.


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## ChrisJ (Nov 27, 2014)

Town said:


> Yes I agree it is easy to do that way except for the rectangular sealing rubber "gasket" on my engine. The rubber gasket will not stay in alignment for me. Bought a new gasket in a kit and same problem. Turning the carb upside down is the only way that I can get the alignment correct so no leaks. The gasket should fit snugly in its groove but doesn't. There are little nubs on the side of the gasket but they don't improve the fit. I don't like using gasket adhesive products.


I think this on is the same, or similiar.
The gasket stayed stuck to the carb every time I took it off so I just consider my self lucky.

For now.

I'm surprised they can justify $900 for a "clone" when a real GX is around that.

Maybe skip the new blower and get a nice Vtwin for the one you've got and get that snow where you want it?


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## NOS (Dec 3, 2021)

I have not yet heard a single person say they are changing the low side jet.

Even wide open the low side is still delivering fuel guy.
As mush as 15% full power.
So if its lean on the low side this problem will continue to manifest itself.

The right way to rejet these things is set the low side up.
I linked a tool called the Gunson Colortune that helps with this.








GUNSONS COLORTUNE SPARK PLUG TEST KIT - LITTLE USED VINTAGE CLASSIC TOOL | eBay


Find many great new & used options and get the best deals for GUNSONS COLORTUNE SPARK PLUG TEST KIT - LITTLE USED VINTAGE CLASSIC TOOL at the best online prices at eBay! Free shipping for many products!



www.ebay.ca




These are getting expensive now but its money well spent.

Once the low side is set and the engine has a good idle you can move onto the main jet and get an accurate reading of plugs


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## harry398 (Jun 22, 2021)

Town said:


> My engine rpm has continued to drop and was down to 3,830 or so but quite variable. Decided to go back to stock main jet. Unfortunately the plastic clip holding the governor rod to the carb throttle assembly broke, allowing the small spring that is also attached to the throttle plate to fully open and the engine over speeded (turned engine off quickly) to about 4,700 rpm and caused the governor counter weights to exit their housing. So engine no longer has an effective governor. Totally my fault for removing the plastic retainer in the cold and breaking 2 of the 4 plastic blades holding it.
> Took off front plate of engine to confirm problem. Likely more damage so engine is toast. A LCT 414cc engine is $900 plus taxes and is on backorder, no used engines available. So a new Ariens 926084 Professional 28" is in my near future.
> 
> Looking at a Princess Auto 420cc engine to fix it and give to my son.


Hey town. 
interesting on the rpm loss....there are variables...........but now you got bigger issues.

Dont write that engine off just yet..but yea you have to pull it apart. 

Id bet you wont find anything major broken.......get it apart...really just rear cover if its like a reg Honda....then you can see what the gov did and see if anything looks broken.

that short burst of rpm wont hurt the shortblock..and as long as you didnt bend a pushrod --i really doubt anything major.


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## NOS (Dec 3, 2021)

valve lash check it cold


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## ChrisJ (Nov 27, 2014)

NOS said:


> I have not yet heard a single person say they are changing the low side jet.
> 
> Even wide open the low side is still delivering fuel guy.
> As mush as 15% full power.
> ...



I've got mixed feelings on this.
First, I didn't know it existed and I do find it interesting.

That being said, I feel a small utility engine falls more into the "good enough" category.

As long as it idles smooth, doesn't hesitate when you crack the throttle wide open and isn't smoking I call it good. 

Judging by the amount of snowblowers I hear hunting every winter, I suspect my standards are higher than most.


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## Town (Jan 31, 2015)

harry398 said:


> Hey town.
> interesting on the rpm loss....there are variables...........but now you got bigger issues.
> 
> Dont write that engine off just yet..but yea you have to pull it apart.
> ...


Thanks for the positive attitude. I did remove the front cover and can see the governor has the 3 weights missing from the cage. I can get the parts from my dealer. The way I took the front cover off caused the camshaft and followers and push rods to become detached and fall into sump, so it will be a job for me to remove the engine and time the camshaft and put it all back together.

The engine did run after the problem occurred. I fixed the governor arm attachment and restarted it and cleared some snow by using the throttle control to keep engine over 3,800 rpm and it occasionally went over 4,000 and I saw 4,500 several times when not under load. So the engine still works fine but my skill level is not up to the job. Guess I need a camshaft installation timing guide.

Princess Auto have a 420cc Pro Point engine that may fit. The electrics seem to be DC which is half rectified from the alternator so my handwarmers and light will be a problem. Not sure how good an engine this is for CAD$499. I don't want to give my son a problem machine.


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## harry398 (Jun 22, 2021)

Town said:


> Thanks for the positive attitude. I did remove the front cover and can see the governor has the 3 weights missing from the cage. I can get the parts from my dealer. The way I took the front cover off caused the camshaft and followers and push rods to become detached and fall into sump, so it will be a job for me to remove the engine and time the camshaft and put it all back together.
> 
> The engine did run after the problem occurred. I fixed the governor arm attachment and restarted it and cleared some snow by using the throttle control to keep engine over 3,800 rpm and it occasionally went over 4,000 and I saw 4,500 several times when not under load. So the engine still works fine but my skill level is not up to the job. Guess I need a camshaft installation timing guide.
> 
> Princess Auto have a 420cc Pro Point engine that may fit. The electrics seem to be DC which is half rectified from the alternator so my handwarmers and light will be a problem. Not sure how good an engine this is for CAD$499. I don't want to give my son a problem machine.



its Not Hard Town. You can handle it. being it ran, I am pretty sure you did Not bend a valve..and you just got to get a new gov assembly. or maybe even put it back together.

the camshaft will have a dot on it...and so will the crank.....line them up--dot to dot....thats how Hondas are...and 99% so will the LCT. *you tube* engine assembly on honda gx390---you will see what I mean. there will most likely be a countershaft...similar...dots WATCH THIS_____.https://www.youtube.com/watch?v=3-gpjLxg_bY







.

camshaft lifter will slide back in, then the camshaft. If possible--keep lifters on original cam lobe. if not...it will be fine, its not a race engine.

I remove the rear cover...and try to save the original gasket...it also acts as a shim for the crank end play. gently work it off with a small flat head .

you can handle it....I know you can. keep us posted, Ill try to help you as you go...


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## Town (Jan 31, 2015)

harry398 said:


> its Not Hard Town. You can handle it. being it ran, I am pretty sure you did Not bend a valve..and you just got to get a new gov assembly. or maybe even put it back together.
> 
> the camshaft will have a dot on it...and so will the crank.....line them up--dot to dot....thats how Hondas are...and 99% so will the LCT. *you tube* engine assembly on honda gx390---you will see what I mean. there will most likely be a countershaft...similar...dots WATCH THIS_____.https://www.youtube.com/watch?v=3-gpjLxg_bY
> 
> ...


Thanks again, that long video helps a lot. Just like a car engine for camshaft alignment, but without the extra complication of chains. The governor assembly looks the same as my engine too, but connection to the governor arm is not shown, so will have to figure that out. The cam followers will end up on different lobes (50% likely). Valve push rods are installed after the engine bottom half is finished. It all seems very easy. That helps a lot; I will remove engine and work on it after I get my new machine.

I needed your encouragement to get my head straightened out.


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## harry398 (Jun 22, 2021)

Lets get er done! 👍 watch a few good vids...and you will be able to master it. gov set up is most likely the same as a honda... 

try your best to save that rear cover gasket.....not sure if they are different than Hondas....The honda gaskets are super cheap....havent needed to look for LCT stuff yet.

after you get the short block buttoned up, remove rocker arms on head, slide pushrods down and then set lash. 

I got a 5 dollar bet you will get it all...


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## NOS (Dec 3, 2021)

ChrisJ said:


> That being said, I feel a small utility engine falls more into the "good enough" category.


Just jetting and timing can add 1 Hp.

No BS


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## Town (Jan 31, 2015)

Found the reason the governor stopped working, the arm that the governor presses against inside the engine is bent and twisted a little and jammed to the case. The governor assembly does not have any weights but the cage moves and pushes the center rod outward and pushes against the black governor arm. Judging by the mark on the arm the governor actuating rod was pushing against the right side of the arm and twisted it so it was pushed sideways against the case.

Pictures attached. First pic shows black governor arm pressed against the case and unmovable; second pic shows the arm moved outward from case in about correct place (except for slight twist); third pic shows governor with 3 arms (no weights) that move the center rod outward to engage the governor arm and move the throttle toward closed position. 

It appears the contact point was to far to the right and pushed the arm to the left at high engine speed. Now that I think I know how the failure occurred I should be able to get the engine fixed ok.


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## 1132le (Feb 23, 2017)

good job mr town side note
i tapped the gov tab to far motor was running 4040 i ran it awhile was thinking i would try it with the new jet at that rpm
i was shooting for 3950
after reading you had issues i put gov spring in middle hole it dropped to 3760 i was at 3850
so i tapped again in 2nd hole and now 3960 rpm
my choke also now works with big jet in before it made no difference
it starts njce cold or hot blows no black smoke
would have liked to try it at 4040 rpm but iam chicken
id imagine outside hole would be 4340 now
you got the skills to fix your motor


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## harry398 (Jun 22, 2021)

Town said:


> Found the reason the governor stopped working, the arm that the governor presses against inside the engine is bent and twisted a little and jammed to the case. The governor assembly does not have any weights but the cage moves and pushes the center rod outward and pushes against the black governor arm. Judging by the mark on the arm the governor actuating rod was pushing against the right side of the arm and twisted it so it was pushed sideways against the case.
> 
> Pictures attached. First pic shows black governor arm pressed against the case and unmovable; second pic shows the arm moved outward from case in about correct place (except for slight twist); third pic shows governor with 3 arms (no weights) that move the center rod outward to engage the governor arm and move the throttle toward closed position.
> 
> ...



Not sure that rod is bent.....or, You should make sure its truely bent. there are washers under the case on that arm....so verifiy easy movement on that.
it may have gotten jammed into a position......but bent ..that has to be verified. also, is it possible that it got a little dislodged and made the gov inop?

2. just check the gov out and see if it spins nice and free..and the tabs move easily. I had a honda gx390 give me some issues one time where the gov wasnt working...just went to 3800 all the time (previous owner did something or it went bad). I replaced the cover with another known good cover with gov assembly and the motor runs fine. so....you still may have a bad governor even though its IN TACT. there are vids out there on how to remove them and its NOT uncommon for Honda governors to go bad --i have heard. I played with that engine for a while and in the end, I am 99% sure it had a bad gov, even though it looked fine.



3 Make sure you get a rear gasket...dont try to just use silicone on rear case cover...as I said before, this gasket space helps determine endplay on crank, so this is important.

Overall, Its about what I expected you to find, no major damage, but I would check motion of gov arm and maybe order a new gov..for 20 bux. I didnt see the camshaft....but i see the counterweight..remember the dots. overall, great news, but still need to find why gov isnt working.


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## harry398 (Jun 22, 2021)

1132le said:


> good job mr town side note
> i tapped the gov tab to far motor was running 4040 i ran it awhile was thinking i would try it with the new jet at that rpm
> i was shooting for 3950
> after reading you had issues i put gov spring in middle hole it dropped to 3760 i was at 3850
> ...



good move 1132. I plan on doing the same exact thing.

dont understand why your choke didnt work. also, I think setting idle at 2200 or lower will give more throttle action/ its a strange set up if you ask me.


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## harry398 (Jun 22, 2021)

here is a basic governor video.


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## harry398 (Jun 22, 2021)

Town...one thing I would def check......Make sure - or check to make sure the gov adj nut was tight. if it got loose or was adjusted wrong, this would also explain no governor action....or incorrect action.

right here is what I mean.....even though this is not a LCT-honda clone engine...you can get my point.


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## harry398 (Jun 22, 2021)

Finally....the simplest---easiest way to adjust a Honda.....as a reference. note the nut...full throttle...then counterclockwise on rod.


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## Town (Jan 31, 2015)

harry398 said:


> Not sure that rod is bent.....or, You should make sure its truely bent. there are washers under the case on that arm....so verifiy easy movement on that.
> it may have gotten jammed into a position......but bent ..that has to be verified. also, is it possible that it got a little dislodged and made the gov inop?
> 
> 2. just check the gov out and see if it spins nice and free..and the tabs move easily. I had a honda gx390 give me some issues one time where the gov wasnt working...just went to 3800 all the time (previous owner did something or it went bad). I replaced the cover with another known good cover with gov assembly and the motor runs fine. so....you still may have a bad governor even though its IN TACT. there are vids out there on how to remove them and its NOT uncommon for Honda governors to go bad --i have heard. I played with that engine for a while and in the end, I am 99% sure it had a bad gov, even though it looked fine.
> ...


Yes, thanks for the input. The governor works as expected and pushes the center rod outward to push against the governor arm. The arm was pressed against the case and could not be moved by hand, it was bent. I forced the arm away from the case to be 1.5" on center from the outside of the case to align with the governor rod that contacts it. I think the governor is fine because the arms move and push the rod outward. 

I will be replacing the gasket since it is broken in a few places. Bearing is still on the crank and seal is in cover, so will replace those as well. Thanks for your help and guidance.


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## harry398 (Jun 22, 2021)

Town said:


> Yes, thanks for the input. The governor works as expected and pushes the center rod outward to push against the governor arm. The arm was pressed against the case and could not be moved by hand, it was bent. I forced the arm away from the case to be 1.5" on center from the outside of the case to align with the governor rod that contacts it. I think the governor is fine because the arms move and push the rod outward.
> 
> I will be replacing the gasket since it is broken in a few places. Bearing is still on the crank and seal is in cover, so will replace those as well. Thanks for your help and guidance.


Hi Town....

doubt you need to replace bearing or seal.....If it was me, I would try to make sure gov issue is solved....test fire up on bench or ground.....before dropping $ into parts that are most likely fine.

gasket, yes.

Hope it goes well for ya!


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## Town (Jan 31, 2015)

harry398 said:


> Town...one thing I would def check......Make sure - or check to make sure the gov adj nut was tight. if it got loose or was adjusted wrong, this would also explain no governor action....or incorrect action.
> 
> right here is what I mean.....even though this is not a LCT-honda clone engine...you can get my point.


That is a good point. The governor always worked perfectly from the factory and i never adjusted the arm and locking nut and bolt. I will ensure that the governor arm touches the governor rod (pin) after installation. Good video.


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## NOS (Dec 3, 2021)

harry398 said:


> You should make sure its truely bent


That's truly bent.....

Best guess is the rod got loose.
The external arm has an adjustment nut.
if it comes loose the arm will eventually get enough slack to hit moving parts inside.

Its very lucky this engine did not wreck because if this...
The plastic gov bits look intact and in good order but he will need a rod internal and have to set the gov up again.
Not a big deal or job, much cheaper than an engine too...


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## NOS (Dec 3, 2021)

Town said:


> Bearing is still on the crank and seal is in cover, so will replace those as well


Leave them.
No need to replace unless there is actually something wrong.
Clones work better once all these parts loosen up and wear.

In racing we used to say loose is fast, but its also reliable as long as they function correct.

There are two holes on the short end of that gov rod where the spring goes.
Inside makes the Gov more sensitive to load changes.
The outer less sensitive, and so less likely to surge and hunt.
Use the outer hole.....


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## Town (Jan 31, 2015)

NOS said:


> Leave them.
> No need to replace unless there is actually something wrong.
> Clones work better once all these parts loosen up and wear.
> 
> ...


Yes the arm is bent but not loose. The governor control spring on the governor arm was in the outer hole but I changed it in an attempt to diagnose the problem. I also adjusted the fixed end of the spring to get up to 3,900 rpm. I intend to reduce engine speed to about 3,700 rpm when I give my machine to my son. 

It is great that you also recommend sticking with the bearing and seal. I will set the governor arm to contact the governor rod as part of replacement process. Thanks for your advice and info on my problem.


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## Town (Jan 31, 2015)

@harry398 and @NOS thank you so much for your help and guidance with my engine problem. I put the parts together this spring and it runs perfectly now. I bent the governor arm into place and reused the main bearing but used a new crank seal that came in set with cover gasket. Reused valve cover gasket and cover. Engine started first time on the electric start and later on the pull start. No oil leaks. The Tach/hour meter is not recording rpm so that needs to be fixed. 

Need to finish putting the rest of machine back together with a lot of new parts for reliability, and then it goes to my younger son for this coming winter.


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## harry398 (Jun 22, 2021)

Town said:


> @harry398 and @NOS thank you so much for your help and guidance with my engine problem. I put the parts together this spring and it runs perfectly now. I bent the governor arm into place and reused the main bearing but used a new crank seal that came in set with cover gasket. Reused valve cover gasket and cover. Engine started first time on the electric start and later on the pull start. No oil leaks. The Tach/hour meter is not recording rpm so that needs to be fixed.
> 
> Need to finish putting the rest of machine back together with a lot of new parts for reliability, and then it goes to my younger son for this coming winter.


EXCELLENT!!!!!!!!!!!!!!!

I am Happy for ya!


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