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Small Engines (Lawn Mowers, etc.)/late 70's-early 80's 8hp Briggs mod.190412


QUESTION: the engine wont run. it sounds like it wants to run by firing at full choke,but wont run. did a compression check and had about 75psi of pressure in the cylinder. when i hold my hand over the carb,it seems to have good suction. when checking the plug after trying to start,it is dry.

ANSWER: Do you have spark?  Will the engine start by priming with a little gas squirted directly into the carburetor?  WD-40 should work to prime the engine as it is flammable but we use a small bottle with a little fuel to prime engines to see if they will start.

Let me know if the engine starts by priming.


---------- FOLLOW-UP ----------

QUESTION: made a leak down tester today and found the exhaust valve wasn't closing tight and must be losing the fuel in the cylinder causing the weak fire with the choke closed. having them ground and will put them back in tomorrow and see what happens. this is a gravity fed carb so i wasn't able to spray ant gas into it.

Gravity carb will not make much of a difference when priming.  Atmospheric pressure will push the fuel into the combustion chamber.  We prime every engine that comes in with "will not start" on the service order.  Priming quickly lets us know the compression and ignition are ok.  This lets us know there is a fuel issue so we start with the carb.

Are you planning on lapping the valves when you re-install them?


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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