QuestionI have a good spark and I even tried squirting a bit of gas in the spark plug chamber. It still did not fire up. So I am guessing compression. Any ideas or sites toi find ways to troubleshoot compression problems? Thank you for your reply.
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Followup To
Question -
I recently cleaned my carb and replaced throttle and govenor springs. I went to tune-up my carb and started the engine. It started with a high RPM as I went to slow the throttle, the engine did not respond. Before I could kill the ignition the engine RPM's fell and then the engine died. After a secong evaluation of the carb, I noticed that the throttle screw had backed out and fell off causing the high RPM's. I replaced the screw and tried to restart. Inow cannot get the engine to restart and there is a irregular noise from the engine block while the engine is trying to turn over. NOT GOOD I EXPECT. I replaced the plug, made some adjustments to the carb jets and still had no luck. The engine is a 1988 BS 11 HP with a cast iron bore. Please advise on possible issues. Thank you!
Answer -
Hi DG,
An engine needs 3 things to run: Proper fuel flow/air mix, spark and compression.
Check for spark at the plug. Squirt fuel into the carbs intake, while trying to start. Do a compression test.
Let me know what you find.
Michael
AnswerI don't know of any sites that would be helpful.
If you don't have or are able to rent a compression gage, you can do a few quick tests, which may indicate a problem. If the problem occured suddenly then I don't suspect a worn piston and rings, so you are looking for a valve problem. Hold your finger tightly over the spark plug hole while cranking over. Does it feel like at least 75psi? Hold your hand over the carb intake. Do you feel suction on the intake stroke? There should be no backpressure during compression.
