# Snow Blower Problem



## mrcolortini (Jul 17, 2009)

I realize that it's a bit early to ask about snowblower repair but it's been pretty cold this July and I heard this winter is going to be murder. I recently acquired a small Mastercraft (MTD) snowblower that will not start. It has a Tecumseh 4.5 hp Snow-King 2-stroke engine with a model 30 carburetor (I was expecting a Quadrajet 4MV) and the unit appears to be less than 10 years old. I pulled the spark plug and it is fouled to the extent that it will not spark. I put in a plug from a running engine (another Tecumseh no less!) and, outside of the combustion chamber, a solid blue spark was seen. In the combustion chamber no ignition whatsoever. The exhaust was cold, there was no tell-tale puff of exhaust, I stuck my finger in the port and there was black, greasy residue in the port. I pulled the replacement plug and it too was fouled. This was after I drained the gas tank. I cranked the engine without the plug and there appeared to be foam on the piston (?) but it might have only been an optical illusion however there was a strong smell of gasoline present and the piston appeared to be wet. I am surmising that the carb is the problem, i.e. it is not metering gas properly and flooding the cylinder. I did notice that gas appeared to be leaking near the choke adjust lever, I believe that the previous owner might have tried to fix the carb or something, gave up and chucked it out. Before I rebuild the carburetor, is there anything else I should consider (besides hibernating until the snow melts)?


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## pyro_maniac69 (Aug 12, 2007)

chances are very good that the carbs needle and seat aren't working properly, ANOTHER thing to check out is since it is a 2 stroke, check your compression, and not the finger test, get a tester and see what kind of compression you have, low compression will give you the same symptoms of a soaked plug, but no fire


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## mrcolortini (Jul 17, 2009)

I never thought about low compression. Needle and seat malfunction or float failure seemed the most likely but I may have to dig out my compression tester. I'm going to attack the carb first (since it is a Tecumseh). It almost feels as if it has a case of hydrolock.


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## hankster (Jan 1, 1998)

You can easily pull the muffler off and look for scoring on the piston and cylinder.


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## mrcolortini (Jul 17, 2009)

Thanks, I never thought of that. The snowblower has been sitting for a few days with the plug out and I blew some compressed air into the cylinder to try to get rid of some of the gas, it still reeks (even 4 feet away the smell is strong) of fuel. I put the spark plug back in the cylinder to see if I could get some ignition. There was no reaction and the plug was fouled yet again and, naturally, the engine cranked much more slowly. I fear that I may have to remove the cylinder head if I can't get rid of the gas by using the air and cranking the engine without the spark plug. I may try to crank the engine again and hope that I can get the piston to BDC and try to send more compressed air into the cylinder. I'm going to open the sheet metal covering that surrounds the engine, remove the muffler and see what I can see. If the engine is this fouled, I wonder how much air is actually going out through the the muffler.

BTW, what are the torque specs for this engine?


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## mrcolortini (Jul 17, 2009)

I'm looking at a muffler, piston and combustion chamber that are still wet after almost a week of being open. The engine still reeks of fuel. It looks like a previous owner was up to something as the flywheel housing appears to to missing a piece and the flywheel is now exposed. I can't see if there is any scoring on the piston, is there anything (spark arrestor?, I haven't looked at a two-stroke engine in a long time) between the piston/combustion cylinder and the muffler I don't know if this would cause a problem with starting. I'm next going see if Mr. Fix-IT went after the carb. How do I post pics, BTW?


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## mrcolortini (Jul 17, 2009)

After cleaning the carb and putting in fresh fuel I still have nothing. It feels like it is flooding. Occasionally I get a puff of white smoke but that's about it. I'm seeing a nice blue spark and have the gap set quite wide to prevent possible fouling. There is one thing though, I cranked once and a spray of fuel came out the choke plate. I wonder if the Welch plugs could be shot and my model 20 Tecumseh carb has an external primer port as opposed to the integral button that I've seen. There is also another tiny port which I haven't figured out yet but I'll try to take some photos and post them here. The piston had some scoring on the skirt but it didn't look too bad.


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## pyro_maniac69 (Aug 12, 2007)

have you done a compression test yet!?!?!?

it REALLY sounds like you don't have enough compression for the engine to run


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## dj722000 (Oct 29, 2008)

Get yourself a compression tester and test your compression. Must be above 95 for it to run right. 100 - 110 I think is better. Im sure I will get corrected on this. And if you acquired this snow blower, who is to say they have mixed fuel in it? 2 Strokes have issues with straight gas trying to fire up. So if it sat for a while with fuel in it, the fuel could have separated and gummed up the carb. If you have plug out, the fuel should mostly evaporate while sitting, if not then its leaking into the cylinder cause your carb is all nasty. Personally I would tear into carb, clean it, put in new parts and reassemble if the engine checks out good. No sense in banging your head off wall for obvious reasons.


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## pyro_maniac69 (Aug 12, 2007)

the 2 stroke snowblower engine WILL run on lower compression

I've seen one run on 45 :lol:

blew snow like a beast too


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