# MTD/Tecumseh won't start - possible electrical?



## gossamer (Apr 25, 2015)

I have an MTD 316E660G552 with a tecumseh HMSK100 159304U 28" that won't start. I recently changed the carb, and it started after that. I confirmed that it's getting fuel by pressing the spring-loaded "button" under the carb and allowing gas to stream out for a while. I've confirmed the engine is getting spark by removing the spark plug, connecting it to the spark plug wire, touching it to the chassis, pulling the starter cord and seeing a spark. I've also confirmed it fires by placing a bit of starting fluid directly into the cylinder/spark plug hole, replacing the spark plug, then pulling the starter cord. It runs for a second then stops.

How can I bypass the removable key to ensure that's not the problem? I had some problems with the wiring when I was replacing the carb and it's possible I either wired it wrong or there is some kind of short? Would it fire at all, even with starting fluid in the spark plug hole if there was a short?

Here's a picture showing what I'm seeing. Number 1 is the wiring to ground and #2 goes to the key. The wire spade terminal broke, so I soldered the wire back onto the terminal for now. It's a solid connection, though. the cover that goes over the carb and supports the key is not pictured here.


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## crazzywolfie (Jun 2, 2014)

sounds like a carb issue. sounds like the main jet needs to be adjusted. the ignition system and wiring is fine since you got it to fire with gas in the cylinder.


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## gossamer (Apr 25, 2015)

crazzywolfie said:


> sounds like a carb issue. sounds like the main jet needs to be adjusted. the ignition system and wiring is fine since you got it to fire with gas in the cylinder.


Thank you. I replaced the carb because I didn't know how to tune the old one 

Is it getting too much gas and flooding? Perhaps I should just return it and get another replacement?


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## crazzywolfie (Jun 2, 2014)

no it sounds like it may not be getting enough if it is not firing under its own but will when you ad some fuel. i would try priming it till you see gas drip on the ground then try firing it up. the engine should at least fire with the way it was tuned when you got it but they still usually require some fine tuning to make they run as good as they should.


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## 1132le (Feb 23, 2017)

in your pic the prime line is not hooked up


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## gossamer (Apr 25, 2015)

1132le said:


> in your pic the prime line is not hooked up


Can you explain further? Is there a hose missing, or you mean an electrical line?


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## crazzywolfie (Jun 2, 2014)

gossamer said:


> Can you explain further? Is there a hose missing, or you mean an electrical line?


just ignore what he said. he needs to look at the picture again because the primer line looks fine from here. if it wasn't hooked up it would be hanging which it is not


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## gossamer (Apr 25, 2015)

Is the primary that needs to be adjusted the screw at the bottom? There are only two screws, and I think the top one is for the throttle/choke.

This is the carb I bought some months ago. I didn't use the spark plug that came with it, but now that I look at it, it looks substantially longer (on the business end) than the original.








Amazon.com: 640084B Carburetor Snow Blower Carburetor Carb Compatible for Tecumseh 5HP MTD 632107A 632107 640084 640084A Toro 521 Snow Blower HSSK40 HSSK50 HS50 LH195SA - for 640084B Snow Blower Carburetor : Patio, Lawn & Garden


Amazon.com: 640084B Carburetor Snow Blower Carburetor Carb Compatible for Tecumseh 5HP MTD 632107A 632107 640084 640084A Toro 521 Snow Blower HSSK40 HSSK50 HS50 LH195SA - for 640084B Snow Blower Carburetor : Patio, Lawn & Garden



www.amazon.com





I'm just trying to make sure I've checked all the boxes to troubleshoot this - it fires and runs with starting fluid, so don't think it would be the spark plug anyway, but it's definitely curious that the new spark plug is so substantially different.


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## 1132le (Feb 23, 2017)

crazzywolfie said:


> just ignore what he said. he needs to look at the picture again because the primer line looks fine from here. if it wasn't hooked up it would be hanging which it is not


its resting on the throttle plate
its not even close to hooked up


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## crazzywolfie (Jun 2, 2014)

gossamer said:


> Is the primary that needs to be adjusted the screw at the bottom? There are only two screws, and I think the top one is for the throttle/choke.


yes the one on the bottom is the main jet. the one on the top is the one to set idle speed and the one on the side is to set idle mixture. i would only adjust the main jet for now but best to try priming it till you see the carb leak gas on the ground. if it doesn't leak gas on the ground while priming the main jet may need to be turned out a bit. 

the sparkplug that comes with the kit is the wrong one. looks like it is for the honda style engines. 


1132le said:


> its resting on the throttle plate
> its not even close to hooked up


it sure look hooked up from here. it looks like it may even need the end snipped off and hooked up again to get rid of the cracked section but other than that it looks hooked up.


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## 1132le (Feb 23, 2017)

gossamer said:


> Is the primary that needs to be adjusted the screw at the bottom? There are only two screws, and I think the top one is for the throttle/choke.
> 
> This is the carb I bought some months ago. I didn't use the spark plug that came with it, but now that I look at it, it looks substantially longer (on the business end) than the original.
> 
> ...


the link you posted is the wrong carb for your engine


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## 1132le (Feb 23, 2017)

gossamer said:


> I have an MTD 316E660G552 with a tecumseh HMSK100 159304U 28" that won't start. I recently changed the carb, and it started after that. I confirmed that it's getting fuel by pressing the spring-loaded "button" under the carb and allowing gas to stream out for a while. I've confirmed the engine is getting spark by removing the spark plug, connecting it to the spark plug wire, touching it to the chassis, pulling the starter cord and seeing a spark. I've also confirmed it fires by placing a bit of starting fluid directly into the cylinder/spark plug hole, replacing the spark plug, then pulling the starter cord. It runs for a second then stops.
> 
> How can I bypass the removable key to ensure that's not the problem? I had some problems with the wiring when I was replacing the carb and it's possible I either wired it wrong or there is some kind of short? Would it fire at all, even with starting fluid in the spark plug hole if there was a short?
> 
> ...


that carb also has a hi speed adjustment bottom of the bowl
low speed adjustment behind the bracket that the engine cover bolts too
hi speed screw bottom of carb 1.5 turns out
low speed screw behind bracket 1 1/4 turns out
warm up for 2 min then adjust them
go watch a video pretty basic
being a member here 7 years id think you should be up on this


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## gossamer (Apr 25, 2015)

Ugh, sorry about that. Here's the proper link to the carb I've installed 

640084B Carburetor Snow Blower Carburetor Carb Compatible for Tecumseh 5HP MTD 632107A 632107 640084 640084A Toro 521 Snow Blower HSSK40 HSSK50 HS50 LH195SA - for 640084B Snow Blower Carburetor https://a.co/d/5R05BwI


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## gossamer (Apr 25, 2015)

1132le said:


> its resting on the throttle plate
> its not even close to hooked up


Would you indicate on my image what you are referring to?

I'm pretty sure all hoses are connected. There's also a continuous flow of gas coming from the bottom of the carb if I press the spring-loaded screw.


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## Big Ed (Feb 10, 2013)

Wow, that plug you show is a lot longer then the old one!
I would be worried about that?


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## 1132le (Feb 23, 2017)

Big Ed said:


> Wow, that plug you show is a lot longer then the old one!
> I would be worried about that?





Big Ed said:


> Wow, that plug you show is a lot longer then the old one!
> I would be worried about that?


ya think? lol
if the op cant figure out thats a piston hitter he needs to stop working on his machine and spen 2 hours on you tube
the L head 8 and 10 hp take about 2 hrs or less to be and expert
research= learn
ask others== rookie forever


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## crazzywolfie (Jun 2, 2014)

gossamer said:


> 640084B Carburetor Snow Blower Carburetor Carb Compatible for Tecumseh 5HP MTD 632107A 632107 640084 640084A Toro 521 Snow Blower HSSK40 HSSK50 HS50 LH195SA - for 640084B Snow Blower Carburetor https://a.co/d/5R05BwI


if that is the kit you ordered looks like it may be the wrong one for that engine. that sparkplug is likely for the OHV Tecumseh and that carb is likely for not the correct one for it. you can try turning the main jet screw clockwise. you might be able to get it to run with that carb. could you also post more pics of the carb? to me it looks like it may be the right carb despite you linking to the wrong carb.


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## db130 (Feb 16, 2013)

@gossamer, are you _sure_ you bought a 640084B? I ask, because that's the carb for a 4-5 hp Tecumseh.

The carburetor for an HMSK100-159304U would be the ubiquitous 632334A carburetor:









Amazon.com : HOOAI 632334A Carburetor for Tecumseh 632370A 632110 632111 632334 632370 632536 640105 Replaces Tecumseh 632334 Carburetor (Normal) : Patio, Lawn & Garden


Amazon.com : HOOAI 632334A Carburetor for Tecumseh 632370A 632110 632111 632334 632370 632536 640105 Replaces Tecumseh 632334 Carburetor (Normal) : Patio, Lawn & Garden



www.amazon.com


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## gossamer (Apr 25, 2015)

crazzywolfie said:


> if that is the kit you ordered looks like it may be the wrong one for that engine. that sparkplug is likely for the OHV Tecumseh and that carb is likely for not the correct one for it. you can try turning the main jet screw clockwise. you might be able to get it to run with that carb. could you also post more pics of the carb? to me it looks like it may be the right carb despite you linking to the wrong carb.


I did get it to start! It indeed just needed some adjustment of the main hi-speed adjustment at the bottom.

Thanks so much for your help. My confusion about the spark plug was that I had a box of spark plugs from different carb kits I've replaced over the last two years, and was wondering how they possibly could have sent that. I knew enough that it was odd, which is why I asked here.

I've been doing this stuff all my life, but very intermittently, and I'm still a novice. This is the third or fourth snowblower I've rebuilt in the last two years, and the carb kits haven't really required any adjustments.


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## crazzywolfie (Jun 2, 2014)

gossamer said:


> I've rebuilt in the last two years, and the carb kits haven't really required any adjustments.


i have also found the same. in most cases the carb straight out of the box will at least run but sometimes require some tuning to run as good as possible since a 8hp and 10 may have slightly different fuel needs. glad to hear you got it running. there is not really too much too them.


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## gossamer (Apr 25, 2015)

db130 said:


> @gossamer, are you _sure_ you bought a 640084B? I ask, because that's the carb for a 4-5 hp Tecumseh.
> 
> The carburetor for an HMSK100-159304U would be the ubiquitous 632334A carburetor:
> 
> ...


I bought the one I posted in July, but I also bought the one you posted in May, so I may have gotten it wrong. I also rebuilt an MTD 24" snowblower that I've already sold, so that was probably for that one. There's no reference on the one I bought in July to the HMSK100, so it must have been the one I bought in May (the same one you posted).

Thank you again for your help.

I tried to rebuild a blown up generator a few years ago and screwed it up beyond repair. I've been a bit hesitant ever since, so maybe that's why I'm asking some newbie questions. I just don't do this often enough to be sure of myself.


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