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


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.

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

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 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.

Small Engines (Lawn Mowers, etc.)

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Eric A. Jones


Lawnmower Repair . Certified Master Service Technician from B&S. Have 23 years experience on B&S, Lawn Chief, Weed Eater, Echo, Peerless, Wheel Horse, Snapper, Atlas, MTD, McCulloch, Homelite and many other numerous brands. Specialize in electrical repair.


Born and raised in the midwest. Started tinkering with engines when I was about 14 on my Suzuki RM-80. I began lawn mower repair at a small hardware store. I knew absolutely nothing. I read lots of repair manuals and met an older fellow who taught me many lessons. I continued working on small engines through high school and paid my way through college working on mowers at the same hardware store. Decided to get away from the midwest and mower repair so I joined the Air Force. I repaired air traffic control electronic equipment and ended up in Hawaii where I got a part time job at Small Engine Clinic. I gained a lot of experience from the Small Engine Clinic and had a blast repairing small engines. I then took the Briggs and Stratton Master Service Technician test and earned my MST. I then traveled to Wisconsin where I attended the factory update training seminar and received formal training. Continued working on mowers part time as I completed 20 years of military. Retired from the military on a Friday and continued in the lawn and garden industry the next Monday.

MAS Aerospace Operations BA Mathematics AAS Electronic Communications AAS Electronic Technology

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