AND as Oletrapper says about 1 tooth off.:
POP or backfire through the ex or muffler when cranking.
You might also consider bringing the piston up to TDC and lock the engine flywheel so as the engine crankshaft cannot move and with the spark plug out inject 10 to 35 psi air into the spark plug hole and listen for escaping air, especially through the exhaust or carb. No need in using over 35 psi.
It will be normal to hear air leaking into the crankcase past the rings. Also remove the oil dip stick or plug so as the crankcase don't hold pressure and you can hear air (confirm) coming out the oil fill hole.
This will tell you if the valves are actually fully closed at TDC. If you hear any air noise coming out the ex or carb you can then remove the valve cover and remove the push rod for the valve in question so as to let the valve close, If air leak stops the valve lash is too tight or as Oletrapper indicates the cam timing is incorrect. (the valve is not closed due to incorrect timing of the camshaft)
To inject air into the spark plug hole I just use a rubber tipped air nozzle or the rubber tip of a compression gauge plumbed to a air source. The air does not have to hard plumbed.
The flywheel will have to be secured good to hold the piston at TDC. Air pressure will try to force the piston down.
If you have a leak down tester you can use it instead of the rubber tipped nozzle for injecting air into the spark plug hole.
POP or backfire through the ex or muffler when cranking.
You might also consider bringing the piston up to TDC and lock the engine flywheel so as the engine crankshaft cannot move and with the spark plug out inject 10 to 35 psi air into the spark plug hole and listen for escaping air, especially through the exhaust or carb. No need in using over 35 psi.
It will be normal to hear air leaking into the crankcase past the rings. Also remove the oil dip stick or plug so as the crankcase don't hold pressure and you can hear air (confirm) coming out the oil fill hole.
This will tell you if the valves are actually fully closed at TDC. If you hear any air noise coming out the ex or carb you can then remove the valve cover and remove the push rod for the valve in question so as to let the valve close, If air leak stops the valve lash is too tight or as Oletrapper indicates the cam timing is incorrect. (the valve is not closed due to incorrect timing of the camshaft)
To inject air into the spark plug hole I just use a rubber tipped air nozzle or the rubber tip of a compression gauge plumbed to a air source. The air does not have to hard plumbed.
The flywheel will have to be secured good to hold the piston at TDC. Air pressure will try to force the piston down.
If you have a leak down tester you can use it instead of the rubber tipped nozzle for injecting air into the spark plug hole.
