# Runs for 15 min, then dies.



## noobie dave (Jan 6, 2015)

Hey ppl, new to the forum. I'm really glad communities like this exist, they've helped me fix all sorts of stuff.

I have an (early 80's?) Honda HS35 single-stage that runs a G150 engine. I bought it used off of Craigslist a few years ago, but it's given me **** ever since.

It will run just fine for about 15 minutes. Then, it will start to lose power, only throwing snow a foot or so. Then, it starts to surge repeatedly; closing the choke keeps it alive for just a little bit longer. Then it dies. A gurgling sound can be heard from the engine, and gas leaks out of the air intake on the carb.

I originally thought it was a vacuum problem, but loosening the gas cap didn't make a difference. Then I thought it was a carburetor problem; I cleaned the carb and that didn't work, so I replaced it with a brand new carb, and that didn't fix it either. The governor springs seem to be in good repair, and the governor moves back and forth as (I think) it should.

With the overabundance of gas when it dies, it appears to be flooding while it runs, which is weird. Perhaps the engine is out of timing, so that the governor pulls away when there's less gas and releases when there's more? I suppose it could be an issue with the carb, but I'm reluctant to think that since the carb is basically brand new.

Any thoughts or leads you guys have would be much appreciated. I'm very handy with a wrench but I'm coming to my wit's end with this piece.


----------



## Normex (Feb 21, 2014)

Welcome to the forum, with this you will have to take it step by step and answer us a few question. First how long the gas in the tank has been?
Is there a gas line filter or there might be one inside the tank, as I would remove all gas in the tank and check the filter. This is what you should start with. Good Luck


----------



## noobie dave (Jan 6, 2015)

Thanks for your response!

The gas has been in there since late summer, but I put Sta-Bil in it. And yes, there's an in-line filter; it was brand new when I installed it late Summer.

Another weird thing I need to add is that when it starts to get weak and surge, if I tip the snowblower back, it will die almost completely; if I put it back down it will continue to run.


----------



## Normex (Feb 21, 2014)

noobie dave said:


> Thanks for your response!
> 
> The gas has been in there since late summer, but I put Sta-Bil in it. And yes, there's an in-line filter; it was brand new when I installed it late Summer.
> 
> Another weird thing I need to add is that when it starts to get weak and surge, if I tip the snowblower back, it will die almost completely; if I put it back down it will continue to run.


 With the ethanol blend some people have problems within a month even with Stabil but before you get further we have to make sure you have good gas delivery from the tank and I would first flush all gas from the tank and even the line and the carb. At that point there's a good chance you also have a filter screen inside the tank and verify if it's plugged a bit and verify your new inline filter by blowing through it. It doesn't take long to replug itself with bad gas. 
On your last item depending on how much gas there is in the tank your small intake tube in the tank could have been installed a bit high hence when level it runs but when inclined no gas is reaching the inside tube. It has been seen before to act as such.


----------



## 43128 (Feb 14, 2014)

you probably have ignition issues, if its the cdi or the excitor thats gone bad, then be prepared to spend 80 for the excitor and another 80 for the cdi module.


----------



## 43128 (Feb 14, 2014)

oh some earlier hs35 revisions had points


----------



## noobie dave (Jan 6, 2015)

I am fairly certain this model has ignition points. they're a pain in the ass to get to, as they're under the flywheel.


----------



## Normex (Feb 21, 2014)

43128 said:


> you probably have ignition issues, if its the cdi or the excitor thats gone bad, then be prepared to spend 80 for the excitor and another 80 for the cdi module.



Wouldn't he just check for sparks after his 15 min. of play and no work?


----------



## scrappy (Dec 7, 2014)

If you know the fuel is ok next thing is check for spark. I use an adjustable gap type set to 'SE' (small engine) Clip it to the sparkplug and run it while watching for spark. Should be a nice bright blue. I have had this one for many years and have solved many automotive, power equipment, and motorcycle ignition problems.


Ignition Spark Tester with Adjustable Gap at National Tool Warehouse


----------



## noobie dave (Jan 6, 2015)

Could I use an automotive timing light?


----------



## Normex (Feb 21, 2014)

scrappy said:


> If you know the fuel is ok next thing is check for spark. I use an adjustable gap type set to 'SE' (small engine) Clip it to the sparkplug and run it while watching for spark. Should be a nice bright blue. I have had this one for many years and have solved many automotive, power equipment, and motorcycle ignition problems.


 Agreed as I wanted to discount any gas delivery problems and then go to ignition. Your ignition testing gizmo is very interesting as I will order one. Thanks


----------



## scrappy (Dec 7, 2014)

noobie dave said:


> Could I use an automotive timing light?


Possible but the results would not be conclusive. We have no idea how low the voltage could go and the light still trigger. Same goes for those neon spark checkers. Seen them fool many a good mechanic.

read this one

http://www.snowblowerforum.com/foru...sion/32489-h60-tecumseh-runs-very-poorly.html


----------



## db9938 (Nov 17, 2013)

noobie dave said:


> Could I use an automotive timing light?


You would need an external 12V source to energize the strobe, but it would not give you any sort of indication of the spark strength. 

Did you replace the plug?


Here's an idea for a DIY spark tester:


----------



## scrappy (Dec 7, 2014)

The fact that you can lean the machine back and it runs better seems like fuel starvation. Maybe remove the fuel hose at the carb and see if it will drain the tank with the cap on. 

If the fuel is known to be good, and the volume of gas available is good, spark verified while running with a gap test, next check would be valve clearance. 

just how i would go about it


----------



## RoyP (Oct 16, 2014)

noobie dave said:


> Thanks for your response!
> 
> The gas has been in there since late summer, but I put Sta-Bil in it. And yes, there's an in-line filter; it was brand new when I installed it late Summer.
> 
> Another weird thing I need to add is that when it starts to get weak and surge, if I tip the snowblower back, it will die almost completely; if I put it back down it will continue to run.


Since you installed the filter.....how old was the machine prior to this filter. Is it possible that the carb has garbage in it prior to your filter install.

Sounds to me like a fuel problem. I would super clean the carb.


----------



## db9938 (Nov 17, 2013)

May also want to consider checking the compression. Some auto parts stores, offer loaner tools.


----------



## nt40lanman (Dec 31, 2012)

I just re-read the OP. The gurgling sound could be a clue. It could be getting hot and boiling the fuel in the carb or line. I'd check for cooling and ventilation.


----------



## scrappy (Dec 7, 2014)

nt40lanman said:


> I just re-read the OP. The gurgling sound could be a clue. It could be getting hot and boiling the fuel in the carb or line. I'd check for cooling and ventilation.


Good thought, maybe a mice nest under the blower cover.


----------



## BobCat520 (Oct 24, 2013)

The fact that it runs OK for 15min's and then can be coaxed a bit by using the choke doesn't send me in the direction of ignition. I'd think your problem is almost for sure fuel related. I had a similar problem in the 60's with a friends Triumph MC. Almost full tank of gas, would run about 15min's or so and starve out, pull over add about a pint of gas and good for another 15min's. In the end the problem was the fuel tank vent in the fill cap was clogged.


----------



## Grunt (Nov 11, 2013)

Possibly a bad or incorrect fuel filter?? There are many types, the ones I am thinking of are about 3/4" thick and 1 1/2" in diameter. The red ones are for gravity systems and the white ones are for engines with fuel pumps. I have heard of fuel delivery issues when a white filter is used on a gravity type system because of the screen size in microns.


----------



## Pathfinder13 (Feb 28, 2014)

My vote is for a bad gas cap which would cause a no fuel condition after a period of time... If you remove the gas cap and then put it back on it would start again and just die again later. Anyway it's one more thing you can check ;-). Gas cap may not be venting


----------



## ToroGuy (Jan 12, 2014)

gas cap vote here too


----------



## noobie dave (Jan 6, 2015)

Thanks everyone for their suggestions, and I'm sorry I've been slow to respond to your much-appreciated help. here's an update:

-I have tried loosening and/or removing the gas cap; it doesn't make a difference.

-The carburetor is brand new, so cleaning related issues, float bowls sticking, etc., shouldn't be part of the problem (but still could be possible).

-Messing with the choke when it starts to die only helps for a little bit; eventually it will die no matter where I hold the choke.

-the fuel filter is a small one recommended by the staff at Advance Auto (experts! amiright?!?!) to replace the stock filter. It could be a problem, and I'll buy some fuel line to test a direct flow without the filter to see if that changes anything.

-I noticed a backfire yesterday. A small, single "Bang!". When the engine seems to die at idle, if I engage the paddles, that will stop the engine from dying and keep it running for a while (5-10 min?) before it dies even with the paddles engaged. Yesterday, it started to die; I engaged the paddles and rammed it into some snow. THere was some sputtering and then a small backfire. I don't know if this is related to the problem or the momentary abuse I gave it.

-I noticed that the oil is pitch black after I added fresh oil only an hour (of operation time) ago, and the level is low. I'm suspicious that there's a valve/piston ring/gasket issue. Or it could be timing. These things stand out, as it's obviously a heat-related issue. Which would lead me to:

-I'm going to try a compression test.

-I'm going to test the spark.

It's supposed to snow tonight; so tomorrow after I plow my driveway (I can still get most of it done before the thing dies) I'll check the spark and compression when it's in its heated"dead" state.


----------



## db9938 (Nov 17, 2013)

By your description of the oil, I suspect you may be on the right track with a ring and/or cylinder question. A quick check of how much blow by in coming out of the breather tube, #11 under the cylinder diagram, will give you a rough idea of degraded things are. It will not be definitive, but you should be able to feel the air moving in both directions, in relatively equal proportions. If there is more moving out, then you should get more invasive.


----------



## Big Ed (Feb 10, 2013)

noobie dave said:


> Another weird thing I need to add is that when it starts to get weak and surge, if I tip the snowblower back, it will die almost completely; if I put it back down it will continue to run.





scrappy said:


> The fact that you can lean the machine back and it runs better seems like fuel starvation. Maybe remove the fuel hose at the carb and see if it will drain the tank with the cap on.


You read it wrong scrappy, see above quote.
Thanks for the spark tester link, I got to get one too.



noobie dave said:


> -the fuel filter is a small one recommended by the staff at Advance Auto (experts! amiright?!?!) to replace the stock filter. It could be a problem, and I'll buy some fuel line to test a direct flow without the filter to see if that changes anything.


You would think so but not necessarily. I guess it depends on the person?
I went to check out the new Advanced Auto parts store in town to see what they had.
I asked if they had any speed nuts and they looked at me like I was an alien.
So I walked around to see what else they had out on display in case I needed something and for prices, there on their bolt rack display there were the speed nuts. 
Though they didn't have my size I pointed it out to them, I then looked at them like they were aliens.


----------



## scrappy (Dec 7, 2014)

Big Ed said:


> You read it wrong scrappy, see above quote.
> Thanks for the spark tester link, I got to get one too.
> 
> 
> ...


Well yeah maybe. It still is part of the puzzle. Without the spark gap test passed everything else is a guess. If the bore and rings were so worn, it would be hard to start cold, oil and vapor pissin out the vent. 

OP, let's get this fixed.


----------



## BobCat520 (Oct 24, 2013)

OK no tank venting issue. Last thing i can think of would be to adjust the valves a few thou looser than spec. I'm not familiar with your motor but if it is a push rod ohv there is a strong possibility when the valve train gets hot and expands one of the valves might not be closing 100%


----------



## bosco659 (Feb 1, 2013)

One of the first things to check when you are having trouble is the compression. Let us know what the readings are when the machine is cold and immediately after it fails after 15 minutes. 

Once it fails, will it start again? If not, how long do you have to wait before it will start again?

I had an old HS35 with the exact same symptoms and it was the coil and it needed rings / valve work. The machine was in good condition so it was worth doing the work (myself).


----------



## scrappy (Dec 7, 2014)

bosco659 said:


> One of the first things to check when you are having trouble is the compression. Let us know what the readings are when the machine is cold and immediately after it fails after 15 minutes.
> 
> Once it fails, will it start again? If not, how long do you have to wait before it will start again?
> 
> I had an old HS35 with the exact same symptoms and it was the coil and it needed rings / valve work. The machine was in good condition so it was worth doing the work (myself).


Can we get another high five for spark test. first...yeah


----------



## bosco659 (Feb 1, 2013)

scrappy said:


> Can we get another high five for spark test. first...yeah


 Agreed! I skimmed over the thread too quickly and didn't notice that important step had not been covered.


----------



## dhazelton (Dec 8, 2014)

My guess would have been a tired magneto that craps out once it get's hot, but checking spark is simple. Also make sure no mice have set up house on the cooling fins or in the exhaust.

I have a 1995ish Snapper rear engine rider I acquired that died after 15 minutes (10 hp Briggs). I changed the fuel cap, magneto, ignition cutoff safety interlock (if you fall off the seat or try to start it in gear) and it still died. I finally just disconnected that interlock circuit from the magneto wiring and it ran fine (not the safest route). I would check everything from the key switch on forward, you may have some wiring that's frayed or the insulation is fried and it's grounding out when things warm up and expand.


----------

