Small Engines (Lawn Mowers, etc.)/TECHUMSE 35 LAWNMOWER


QUESTION: hi tried to reply to your answer on my machine but the system wouldn't allow it! techumse says  valves 4&8  thou setting so i imagine the first figure is the inlet checked mine i have 7&11 would that make a difference? 3 thou of dirt on the seatings can you suggest any thing else please or is it a matter of scrapping it? thanks eric much appreciated.

ANSWER: .007 and .011 of and inch will effect the timing slightly but the compression is what you would would have more compression.

You can lengthen the valves a little by carefully peening with a hammer but this is not the preferred method to obtaining the correct clearance.

If the head is still on the engine I would torque the head bolts and then quickly rotate the engine counter clockwise.  If the flywheel snaps back the other direction then there should be enough compression to run.  This is the old compression method test Briggs used to publish in their service manual.  Keep you hands out of the way as you can catch your fingers in the flywheel.

Compression test You Tube video:


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QUESTION: morning ive tried every trick in the book still not starting!but what ive noticed is that there is a strong puff of air coming out of the breather hole on the inspection cover of the valves no plug in just turned over by hand is this back pressure? & could that prevent it from starting ? valves are fine  good spark , clean carburettor keyway good know  knocks or bangs its baffiling thanks den

ANSWER: Is the flywheel key sheared?


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QUESTION: no !its fine checked it with a new one

You could get a puff of air coming out of the breather hole when you turn the engine by hand.

Do you have a compression gauge to measure the engines compression?

Are you familiar with priming an engine by using a small squirt bottle with a little gas in it and squirting the fuel directly into the carburetor?

Let me know.

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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