2 stroke tecumseh help
 

Hey guys (and gals? any left ?)

I have this snowblower....same old story - got it free a few years ago, got it running and used it every once in a while: its a 2-stroke, single stage, "Toro S-140" thing. It is powered by a small, tecumseh 2 stroke engine with a chain driving the paddles.

Every year, I take the carb. apart and clean the junk out. Last year I threw a carb rebuild kit at it (new diaphragm and a few gaskets). I thought that I ran it out of fuel last spring, but when I had the carb. apart today, it was full of powdered fuel residue (?).

Every year - it gives me the same problem - starts and runs on the primer, but refuses to run normally. Sometimes I can get it up to temperature and it'll stay running long enough to shovel snow (rpms oscillate a lot though). But this year it happened again (after I cleaned out the carb) and just doesnt stay running.

I'll push the primer button once or twice, it'll run for 1 to 5 seconds (on the 1st pull) and then give up. manually fiddling the throttle does nothing. Sometimes I can keep it going by continually 'pumping' the primer button

The only thing I havent replaced is the rubber primer 'button' and associated hose. On this model, the primer button is mounted to a 'control panel' and is connected to the bottom of the carb via a 4" piece of tubing. The air pressure from the primer button goes to the underside of the diaphragm...I'm not sure why this would keep a engine from running.

the diaphragm is new as of last year - no visible tears but small rubbers are sometimes deceiving...

Spark is strong, compression feels good (havent checked). These things aren't tough to figure out - what am I missing ?

-John

Two-smoke engine with hard starting? Have you checked the crank seals?

Last years gas mix or fresh?

I've got a couple of those 2 stroke snow blowers. I've concluded that the amount of time I spent getting them running each year was better spent just shoveling the snow. I haven't fired them up in years. Just get an electric one.

Way back, about 1966 I was working in a gas station, and the owner was also a Toro dealer. We used the gas "shovel" to clear snow from the lot. That was when I learned the valuable lesson that you always mix the gas and oil in a can; not the tank. I added gas, then oil, and started it up. It started quickly and ran well, the RPMs then kept on going up, and up, until the crank exited the bottom of the crankcase. ( I thought the crankcase was to "contain" the crank. It did not serve that function well---must have been a design fault......).
I was then assigned a manual snow shovel.

If the crank seals were bad, it wouldn't run at all. That diaphragm carburetor does not have a very good track record and is difficult to repair. The best bet would be a replacement if you can find one, or see if the engine can be updated to a float carburetor.

Depends on the level of leakage...

Agreed. A lot of times a small leak at the crank seals is what causes temperamental two strokes

Harbour freight has a very good four stroke engine they put up on sale occasionally for less than a hundred. Six point five horse Chinese model with a really good reputation. If it would fit your set up might be a good option.

excellent ideas guys - thank you.
I didnt think about hf - I love that place as much as a despise it :) I think that I'm in the 1 to 3 hp category....but again...if HF has something....

I've never separated the engine from the rest of the snowblower, but if float-y carbs exist for this model, I might ask about it at my local small engine junkyard.

Thank you all,
-John