Small Engines (Lawn Mowers, etc.): Tecumseh H80 8hp throttle

Question
Will try to be brief.Just purchased used snowblower with 8hp,H80 motor.Starts fine,idles so-so,but when I try to use throttle to rev up engine,it sputters,seems to knock,backfires through muffler and will stall unless I back off.It had a broken throttle cable, but I fixed that,thinking it was problem.Checked all linkages as per articles on internet.I was told that carb was cleaned,is there a possibility it is carb related?It seems to be the only thing left other than internal motor issues.

Answer
I'd start with the carb and make sure it is clean.  You can find the manual at the URL below:

http://www.smallenginesuppliers.com/html/engine-specs/tecumseh/Tecumseh_L-Head_E

If this not your manual let me know the full engine model and spec number.  It should be fine for cleaning the carb.

You can also look for You Tube videos...lots of videos on carb rebuilding and cleaning.

Pay attention to how the carburetor linkages are connected.  MARK the holes and takes a few pictures of the connections and linkage routing...will make putting it back together much easier.

DO NOT mess with governor or governor arm...you can remove the carb without messing with the governor.

You could have a valve issue or ignition issue but most likely it is a carb running too lean.  Also, on older Tecumseh engines, make sure the head bolts are properly torqued to specifications in the manual.

Let me know if cleaning the carb improves engine performance.
Eric