Small Engines (Lawn Mowers, etc.)/9hp craftman snow blower


QUESTION: I don't know why is oil came out from breather hole a lot,& I can see my muffler all red when engine is running, anyway I can fix or I need a new engine?

ANSWER: Does the oil smell like gasoline?  Is the oil really thin and runny?   When was the last time you changed the oil?  How old is the engine?  Do you have a Tecumseh engine on the snowblower?

The red muffler means the engine is running too hot.

Let me know what the engine model and type number are as well.


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QUESTION: my snow blower model # is 247-888530, but I seen another tag on the engine itself; engine model # is 143-029001, engine family # 1tpxs-3182bf, my oil smell fresh because I changed every year, but I did changed carburater last year, I took valve cover off & check, everytime I hit the start button, I saw oil blew out of hole between 2 valve.

The engine is a Tecumseh HMSK90-156534E (model-spec).

Engine repair manual URL:

Look on page 76, third column, "Breather Passing Oil".

The breather could be malfunctioning or an o-ring or gasket may be leaking.  These engine rarely have a leaky o-ring or gasket but I would check a few locations.  Check the dipstick if you have one, these o-rings can leak.  Check the head gasket, actually check the head bolt torque to ensure all the bolts are correctly torqued.  Finally check the intake gaskets to make sure they are not leaking.

If you have a cylinder leak -down tester I would perform a leak-down test to check the condition of the rings, valve components, and head gasket.  Another test you can perform is a crankcase vacuum check.  Tecumseh does not publish vacuum specs but the important thing is that the crankcase is maintaining a little vacuum to help keep the oil in the engine crankcase.

Breathers are easy to clean and based on your problem I would clean the valve breather.

Use the service manual to find the engine head bolt torque...I have had loose head bolts on Tecumseh engine cause weird problems.


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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