QuestionQUESTION: I have a hasquvarna lawn tractor with 12.5 hp Briggs & Stratton Vanguard Engine Model 28P777 Type 0134 01. I have replaced the carb, replaced all fuel lines, cleaned tank, and rewired entire mower. The engine runs great for ten minutes or so and then dies. It will not restart untill an hour or so later. I am at a loss with this.
ANSWER: Have you checked to see if the engine has spark when it dies? Use and inline spark tester to test for spark as soon as it dies.
You may have a bad coil that fails when it gets hot. Have you replaced the spark plug? Do you have a brand new spark plug that you can install when the mower dies? Will it start with a new plug in the hot engine?
Let me know.
Eric
---------- FOLLOW-UP ----------
QUESTION: I checked the spark when the engine died, and there is a slight spark. I checked again when it was cool and it was much more aparrent. I put a new plug in when it stalled, but that did nothing. Even with a slight spark should't the engine fire?
Jake
AnswerI have had one coil with weak spark. Since you have replaced the carb I'm betting the coil is breaking down when it gets hot causing a weak spark.
You can buy an inline spark tester from your local auto or small engine dealer for around $10-$20 bucks but from what you have already done the coil sounds like the problem so you may want to just put the money on a new coil.
Eric
