My 15 hp Johnson has low compression; ~60-70 both cylinders.
It also has low flow out the tell-tale (I replaced the impeller with no real effect and will check the gromment on the water tube shortly). Hoping for the lesser of possible evils, I checked the head gasket hoping that a warm engine (due to a dislodged grommet?) caused it to leak. However, after pulling it last night, I could not find any indication that it leaked.
The cylinder walls are completely smooth and the pistions glide easily. I grabbed the pistons and tried to shake them to see how much play there was between them and the cylinder walls. I got very little movement as one would expect. But how much is too much?...I don't know.
What else could be causing low compression?
Any help or insight would be greatly appreciated.
Thanks in advance
It also has low flow out the tell-tale (I replaced the impeller with no real effect and will check the gromment on the water tube shortly). Hoping for the lesser of possible evils, I checked the head gasket hoping that a warm engine (due to a dislodged grommet?) caused it to leak. However, after pulling it last night, I could not find any indication that it leaked.
The cylinder walls are completely smooth and the pistions glide easily. I grabbed the pistons and tried to shake them to see how much play there was between them and the cylinder walls. I got very little movement as one would expect. But how much is too much?...I don't know.
What else could be causing low compression?
Any help or insight would be greatly appreciated.
Thanks in advance