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Small Engines (Lawn Mowers, etc.)/Briggs & Stratton will only run on choke


I have a Briggs 5hp model # 135202 on my Trac-Vac leaf shredding machine. It is a suction feed carb with no mixture adjustment capability. Every time I use it, the engine operates normally for a few minutes, them will only run with the choke on, often stalling out and needing restarting several times, until I am finished using it. I have had the carb apart several times, blowing it out with compressed air and carb cleaner. When reassembled the engine usually works fine for the first time I use it, and then it reverts back the same trouble again. Needing the choke on, suggests a lean condition. I am about at my wit's end dealing with this. I also replaced the spark plug and checked the gas cap for venting with no success. Can you please give me any direction on where to look to find and fix this problem?

How old is the engine?  The first 2 digets of the code number indicate the year.

How many hours are on the engine?

Is there a very fine screen on the short fuel tube?
Have you checked the head bolt torque?  Once had a leaking head bolt that I thought was the carb...did the same thing as a while, quit, run on choke.


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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