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Small Engines (Lawn Mowers, etc.)/Kawasaki FC290V BS02 John Deere Rx 75


QUESTION: Hi Eric, question concerning john deere rx-75 kawasaki fc-290v BS02 serial # FC290-060962. Forgot to turn off fuel at end of season,contaminated oil w/ gas. Started engine up and white smoke like crazy, some fuel/oil coming out of exhaust pipe. Drained all oil out and let sit for a day, fresh oil added and run for 5 min, drained oil and refiled w/ new. Started right up, but still smoking like mad (white smoke). No oil in carb and breather pipe seems to be blowing air into carb. Can't seem to locate crankcase breather  valve to check it. Looked under valve cover but still can't find it. Maybe blown head gasket? Any help please!

ANSWER: Doubt the head gasket is blown.  I bet there is a lot of oily gas in the muffler that is smoking like mad.

Go the the URL below and get the manual:

Check for engine crankcase vacuum.

If you have a leakdown tester, or even a compression gauge, you can get and idea of the internal engine condition.


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

QUESTION: Thank you for your quick response. How do I check for crankcase vacuum? I do have a compression tester and will do a test. I am looking for around 70psi correct?

70 psi might be a reach depending on the age.

The service manual should state the expected compression...there are some differences between manuals but 70 would be good.

There are several methods for checking vacuum.  You can use a manometer or a vacuum gauge.  Most technicians just drill a hole in a rubber cork and use a vacuum gauge.  There are a few videos on You Tube on checking small engine vacuum.

Do you have a leakdown tester?  This is the preferred test for checking rings and valves.  Handy tool but can be pricey.


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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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