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Small Engines (Lawn Mowers, etc.)/craftsman 5.0hp 22cut blowing oil up through cyl hd


hi eric I have a 5.0hp craftsman techumse engine 22 cut and it is blowing oil up through the cyl hd. afriend of mine told me there is an engine vent that is possibly plugged however I cannot see a vent on it is this possible. I was thinking  it may be a ring issue. I would greatly appreciate your thoughts on this issue. thanks

Is the engine oil level too high, over filled with oil?  Does the oil smell like gasoline or is the oil really thin and runny?

There is a breather on all engine.

Service manual:

From page 78
1. Check the oil level, make sure the engine is not overfilled. Also verify that the viscosity rating on the container of the oil being used is to specification.
2. Check the angle of operation. Avoid prolonged use at a severe angle.
3. Check the engine R.P.M. setting for excessive R.P.M. using a vibratach or other tachometer and compare it to the R.P.M. settings found on microfiche card # 30 according to the engine model and specification number. Adjust the high and low R.P.M. as necessary.
4. Check for leaking or damaged gaskets, seals, or "O"-rings. External leaks may not be evident; however, the leak may prevent the engine from achieving a partial crankcase vacuum.
5. Check the breather for damage, dirty condition, or improper installation. The oil return hole(s) must face down.
6. Check the engine compression using a compression tester. If the engine has weak compression, determine the cause of weak compression: worn rings, leaking head gasket, or leaking valves. Follow the compression tester's procedure.

Let me know about the oil and if the manual helps.

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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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