Engine won"t idle

R

rocket1

Well-known member
On returning from a 60 mile ride whenever I stopped the engine would die,checking it out at home I could hear a miss in the exhaust pipe and a crackling noise at the carb.I took a compression test and found only 40 lbs at number one cylinder and 60 to 70 on the others.I pressurized #1 cylinder with 60 lbs air at top dead center,air leaks out the carb;also with the #2 plug out the air will come out #2 cylinder while #1 is under pressure.I assume #1 intake valve is not seating or burned but why is air coming out # 2 plug hole?
 
If #1 is finishing compression cycle and the intake valve is not completely closing and #2 is in it's intake cycle with the intake valve open you could have this condition. You might try your test with the #1 piston more retarded in its relative position were the #2 intake is positively closed.
 
You have done the right checks, so it's time to remove the cylinder head, and open the valve chamber. Your best expectation should be a failed head gasket and a burned valve.
 
I don't think I'd worry about the head gasket just yet. Could the #1 hole have a sticky valve ? Have you checked the lash on that valve ? If that valve is bad it could leak into #2, in that case the head would need to come off.
 
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