Small Engines (Lawn Mowers, etc.)/gasoline in oil


Hello we have a briggs n stratten 17.5 hp riding mower..recently we started the mower and blue smoke came billowing out of the from part of the mower where the exaust is..i called the manufacturer and he told me to rebuild the carb and so I did..there is still smoke and oily gasoline coming out from the exaust area..can you tell me what to do next??


This a very common problem...a leaky carburetor inlet needle.  This can be caused by a number of things.

Did you replace the inlet needle and seat if the seat was replaceable?

If so, the simplest solution to solve your issue it to install an inline shut-off valve; less than $10.00 and should be readily available from any mower shop.

What is the engine model, type and code number?

Make sure you DRAIN and REFILL the oil.

The shut-off valve will solve your problem...YOU just have to REMEMBER to shut it OFF when you are done mowing.

FYI, I install inline shut-off valves on my own personal mowers...yes, mowers...mower than I need but they all have shut-off valves so I don't have to worry about gas leaking past the carb inlet needle seat and entering the engine oil.


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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