# Smoking tractor- now what do I do?



## Wlivesey (Nov 27, 2011)

I am feeling pretty frustrated with my lawn tractor. I have tried to fix as much as I can right now and I am hoping you all can provide some advice on (1) what is the likely problem and (2) what do you think should be my next steps. 
Problem: Blue smoke out of the exhaust after it warms up. This just recently started happening and seemed to happen all of a sudden. If I check the oil after it has been smoking, I also see smoke comming out of the oil dip stick tube. Also seems to have a loss of power. 
Tractor: Sears Model 917.28910; 20 HP Briggs & Stratton model 331777. 3 years old.
Use: Grass & leaf cleanup. I think I must have less than 200 hrs total in use.
Done so far to fix the problem:
1. Checked that the engine fins were not clogged - they were OK - I did clean out what little junk was there
2. Checked oil level - it was not overfiiled. Changed the oil. In the past I have changed the oil only once every year. Is that enough?
3. Checked air filter - looked OK, but tried to bag out any dust. I also tried vacuuming it. In the end I recently replaced it.
4. Spark Plug - spark plug was dry but black with carbon build up on it. This was the original plug. I replaced the plug.
5. Gas - Cleaned out the gas tank and put in fresh gas
6. Carburetor - Took it apart. Appeared very clean to me. I did not see any varnish or any residue. I blew it out and put it back together.

Let me know what you think. I am hoping with your help I can fix this tractor.
Bill L


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## HYDROGUARDIAN16 (Feb 14, 2007)

Sounds like a head gasket problem. I've done a ton of them on that motor earlier this summer and they did the same thing. The gasket leaks near the valves. Briggs part no: 794114


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## Thomas (Nov 1, 2006)

Welcome Bill.
Also agree w/HYDROGUARDIAN16,I wouldn't use tractor until repair...


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## Wlivesey (Nov 27, 2011)

Yesterday I replaced the headgasket. No torque wrench so I tightened it up as evenly as I could. When it started up it blew smoke for maybe 4-5 minutes - but that was the end of the smoke. And it now seems to run good - no problems. Now I need to ask...how can I prevent this from happening in another couple of years? 

I also want to thank you for your quick and accurate diagnosis. Thanks alot - 1 less thing to worry about...I do appreciate your help!
Bill L


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## Country Boy (Mar 18, 2010)

The head gasket problem on the Briggs & Stratton Intek engines is well known, and there really isn't much you can do about it. There isn't enough compression in the one area of the gasket due to a design "flaw" which allows the gasket to burn away after a while. I have changed a ton of them over the years in the shop at work. I'd recommend picking up a torque wrench (or borrowing one) if you ever replace it again.


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## dangeroustoys56 (Jul 26, 2010)

I had a similar issue with my 85 mastercut 12HP flatty briggs - power was okay still, just one day started smoking horribly - its ran great since the day i brot it home, i dont really use it often tho- usually fires right up and runs - i started mowing the yard and all of a sudden it smoked horribly - i shut it off and pushed it back to the shed.

There was oil in the carb, with some disassembly - noticed the head bolts were loose - so pulled that and saw a blown head gasket - i had a spare used HG ( yeah i know theyre only a one time use) which was still decent looking - slapped that on, changed the head ( in case it warped) with a spare , changed the oil breather - ran pretty good till my used HG let loose ( noticed a change in the loudness of the motor) - its on my list for a new HG .

The flatheads are by far easier to change the HG's....


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