# Tecumseh 10 HP Snowking HMSK100



## Bob DiGiacomo (Jan 15, 2009)

Hi,
This snowblower engine starts easy, but does not run correctly. I replaced the carburetor already. The compression is 120Psi. The engine can run pretty well, but makes a little pop sound like it is getting too much fuel, maybe? I can adjust the adjustable bowl nut to add more fuel and speed up the rpm, but it continues to bog down in snow. I work on many of these engines, but I don't have professional training. Is it possible the spring on the throttle lever can be worn (it is rusted and weak) and cause these type of problems? Or is this a fuel problem, that I am somehow missing. Any help would be great. Thanks

Tecumseh hmsk100 159295V.


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## Sir Thomas (Dec 7, 2013)

Sounds more like an ignition issue to me. You may be getting a misfire. Searching online I notice this engine has the magneto coil underneath the flywheel. You have a tester (they have them a NAPPA) to check your spark. With the tester you can see if you are getting a clean consistent spark.


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## geogrubb (Jul 28, 2006)

Bob DiGiacomo said:


> Hi,
> This snowblower engine starts easy, but does not run correctly. I replaced the carburetor already. The compression is 120Psi. The engine can run pretty well, but makes a little pop sound like it is getting too much fuel, maybe? I can adjust the adjustable bowl nut to add more fuel and speed up the rpm, but it continues to bog down in snow. I work on many of these engines, but I don't have professional training. Is it possible the spring on the throttle lever can be worn (it is rusted and weak) and cause these type of problems? Or is this a fuel problem, that I am somehow missing. Any help would be great. Thanks
> 
> Tecumseh hmsk100 159295V.


It sounds like a timing issue, it may have a partially sheared flywheel key, someone was throwing snow and picked up the newspaper from the driveway and everything stopped except the flywheel. Have a good one. Geo


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## Rentahusband (Aug 25, 2008)

Agree with checking the flywheel key. I have also come across a few of these engines where the springs on the throttle bracket needed a little WD-40. One was brought to me as the repair shop told the owner the exhaust valve was burned and needed replacing. I do not think they even took it apart. I found the valve was fine and that these springs were not working properly. I sprayed it with WD-40 and the engine ran fine.


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## Sir Thomas (Dec 7, 2013)

*Flywheel Key*

When the key on my 5 horse Brigg and Straton sheared, it wouldn't even crank. I don't know if the Tecumseh is different. Perhaps it is sheared but not spinning because the bolt is holding it in place, just slipped a tad. Wouldn't take much to throw the timing off.


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## Bob DiGiacomo (Jan 15, 2009)

Thanks for the help. I don't think it has a sheared flywheel key because there is no kickback at all when pull starting, but it is easy to check so I will. I have a spark tester I will recheck the spark. I just replaced the head gasket and checked the valves. They seat well and I can not turn them by hand at TDC the clearance is .006 for both the valves. The exhaust should be .012, but the engine starts very easy and there is no backfiring, so I will leave them alone for now. I really think I have a fuel related problem, so I'm going to check the flywheel key, replace the fuel line and fuel shut off that runs behind the shroud, and test spark again. I will come back with the results. Gas cap is vented I switched caps already. Thanks


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## Bob DiGiacomo (Jan 15, 2009)

geogrubb said:


> It sounds like a timing issue, it may have a partially sheared flywheel key, someone was throwing snow and picked up the newspaper from the driveway and everything stopped except the flywheel. Have a good one. Geo


That was yesterdays project on someone else's snowblower. I had to remove the chute and I used an oscilating saw to gradually vibrate and cut away the newspaper. It was stuck in there like concrete. Amazing. It took me 40 minutes to get it out.


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## paulr44 (Oct 14, 2008)

Bob DiGiacomo said:


> That was yesterdays project on someone else's snowblower. I had to remove the chute and I used an oscilating saw to gradually vibrate and cut away the newspaper. It was stuck in there like concrete. Amazing. It took me 40 minutes to get it out.


My fav story is of a lady brought in her snowblower that just "stopped working." After fixing it, I told her I knew she was clearing the plowed-up snow by the curb or driveway when it quit. She said "yes, how'd you know?"

I said, you had a "flat, frozen squirrel jammed under the auger rakes."


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## paulr44 (Oct 14, 2008)

Bob DiGiacomo said:


> Thanks for the help. I don't think it has a sheared flywheel key because there is no kickback at all when pull starting, but it is easy to check so I will. I have a spark tester I will recheck the spark. I just replaced the head gasket and checked the valves. They seat well and I can not turn them by hand at TDC the clearance is .006 for both the valves. The exhaust should be .012, but the engine starts very easy and there is no backfiring, so I will leave them alone for now. I really think I have a fuel related problem, so I'm going to check the flywheel key, replace the fuel line and fuel shut off that runs behind the shroud, and test spark again. I will come back with the results. Gas cap is vented I switched caps already. Thanks


While I'm skeptical about the flywheel key, it isn't out of the question just very, very rare on a belt-driven unit. Given your detailed info. and having a new carb. on, I'd suggest you check the governor / carb. linkage for binding or interference, it may be you have the link in the wrong hole on the carb. plate. After that, reset the governor "free play." SEARCH this forum for GOVERNOR STATIC ADJUSTMENT which should always be done when replacing a carb. It's possible the governor spool has a groove worn in it from dirty oil, which would cause it to be slow or unresponsive to loads. The popping you describe may be nothing, but can definitely be an ignition concern which is why you're being pointed to the fly. key. Base carb. mixture settings should be about 1 and 1/2 turn to 1 and 3/4 turn out for the bottom (high speed) screw, and 1 turn out for the side (idle) mixture screw.

Whenever working on Tecumseh engines, IT IS VITAL to check the tank flow, and thus the screen for restriction. With the tank removed, drained, inverted and fuel line off, I spray carb. cleaner into the nipple to clean the screen. Then, I fill it with parts washer solution, invert it and while it draining out (creating suction for air at the nipple) I spray more cleaner in the nipple. Then I flip it right-side up and put parts wash. sol. back in to check flow out the nipple.

Simple things like this can fudge you up, like a tank cap vent (which we've seen a lot of failed caps in the last few years on these engines).


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## Bob DiGiacomo (Jan 15, 2009)

Thanks for all the help and suggestions. Good News I got it running. I removed the flywheel to check the key and it was good. I noticed that the old fuel line that runs behind the shroud had evidence of a flat spot from where the edge of the shroud was pushing against the fuel line, so I replaced the fuel line and made sure the shroud was not putting too much pressure on it (dumb design). I removed the coil and cleaned all the surfaces with the wire brush there was alot of rust, but under the bolt heads it looks somewhat okay. There was a set of studs where the coil bolts to I pulled them and wire brushed them as well. Started it up and adjusted the air/fuel mix, and that thing has no issues in old heavy wet snow (well it is no match compared to my 11.5 HP ariens), but for an MTD it does pretty well. Thanks again for your help. My guess is the problem ended up being either a collapsing fuel line or a pinched fuel line and the work on the coil can only help out. It usually is something simple (man did I waste alot of time screwing around with the new carburetor, and it the end I ended up putting the old one back on.


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## Sir Thomas (Dec 7, 2013)

Bob DiGiacomo said:


> Thanks for all the help and suggestions. Good News I got it running. I removed the flywheel to check the key and it was good. I noticed that the old fuel line that runs behind the shroud had evidence of a flat spot from where the edge of the shroud was pushing against the fuel line, so I replaced the fuel line and made sure the shroud was not putting too much pressure on it (dumb design). I removed the coil and cleaned all the surfaces with the wire brush there was alot of rust, but under the bolt heads it looks somewhat okay. There was a set of studs where the coil bolts to I pulled them and wire brushed them as well. Started it up and adjusted the air/fuel mix, and that thing has no issues in old heavy wet snow (well it is no match compared to my 11.5 HP ariens), but for an MTD it does pretty well. Thanks again for your help. My guess is the problem ended up being either a collapsing fuel line or a pinched fuel line and the work on the coil can only help out. It usually is something simple (man did I waste alot of time screwing around with the new carburetor, and it the end I ended up putting the old one back on.


Join the club bro. I blew money on a ignition coil for a blower when compression was the real issue. Got the compression issue fixed but busted the key (built into the flywheel) because I didn't tighten it down properly. I'm so used to working on 4 cycle engine. 2 cycle is new stuff for me.


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