QuestionQUESTION: I have a Toro riding mower with a Briggs/Stratton model 286707 type 045201. I recently purchased it and it worked for about an hour. The next day it would not start. I checked for spark and fuel appearing to have both. I then checked compression and it ranged from 5-10 lbs. of compression. What are my next steps to get it running again?
ANSWER: You need to find out if one of the valves is being held open causing no compression. Just a few days ago my brother-law called me with a similar problem and found his valve guide had come loose causing the valve to stay open.
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QUESTION: How do I check to find out if the valves are being held open. Do I have to take off the carb? I turned the flywheel in both directions with no resistance or bounce back in either direction.I have never taken an engine apart or tried to fix an engine with low compression. I want to learn more fixing the engine than fixing the engine itself.
AnswerBehind the carburetor is the breather plate, you have to remove both the carburetor and breather to view the valve stems. when looking at them, rotate the engine and observe if they are moving or not. When they close, view if there is a large gap between the valve stem and pushrod, the gap should be VERY small, approx. .006". If there is a large gap, you probably have a stuck valve, and this will probably need to be repaired by a qualified technician.
