Tecumseh carb question

[crosstalk]

Hello. I have a sears craftsman snowblower with tecumseh HM80-155321L (serial 6290C). I can't get it started and noticed the primer bulb is shooting air out of the atmospheric vent hole in the body of the carb. I think the main jet (adjustable) is too corroded (kind of rough on the tip portion). I ordered a rebuild kit #632347, but I am wondering if I have a more serious problem with the carb. Is the primer not pushing fuel up the main nozzle because the jet is corroded or is something else wrong?

[crosstalk]

The two holes in the body of the carb that transfer fuel into the main jet were completely blocked so I suspect this was the problem. I need to wait for the kit before putting it back together--hopefully I solved the problem.

[38racing]

small idle just below upper thread section needs to be clear too plus other passages in carb

[crosstalk]

I cleaned the carb (didn't remove welch plugs) and installed the repair kit parts. Engine starts now but runs too rich and surges badly. New spark plug became sooty after just a couple of minutes of running. Compression (hot) is 140 psi with the electric starter turning over the engine. Did a static governor adjustment, but that didn't help. I can't seem to dial the high speed carb adjustment into anything to prevent the surging, backfiring out the muffler and spitting out the carb. Is it time to pull the head to check valve clearances/decarbon or am I missing something with the carb adjustment?

[KE4AVB]

Did you check and set the float height?

[crosstalk]

Thanks for the reply. Yes, I set the float height with an 11/64" drill bit as described in the l-head manual. The float isn't level with the body at this setting though (seems like that is ok with tecumseh carbs according to other posts here). I guess I need to pull the intake off to get access to check the valve clearance.

[bgsengine]

Try a new spark plug.

[crosstalk]

Thanks. I tried running with a new spark plug for a few minutes then pulled it to check it. It was covered in dry carbon. Btw, I am not completely sure what spark plug I should be running in this engine. It came to me with a champion j19lm.

[Mek-a-nik]

That plug is right.

If it's rich, and the float isn't too high, track down where the gas and air are mixed in the carb. Air is added to the gas between the jet and the tip of the emulsion tube that sticks into the airstream in the venturi. Find where the air is supposed to come from. If the venturi is drawing all gas into the venturi, and not drawing a gas/air mixture into the venturi, the source of the air that should be mixed is probably blocked, causing an all-gas, not an air/gas mixture to pulled into the airstream.

Whew, that's hard to write! I hope I'm being clear.

[38racing]

Since not mentioned are you sure the choke is fully open?