Hey all. I was given a 1975 Mercury 650 65 hp 3 cyl dual carb outboard motor (SN# 4267140)
and boat with trailer.
He said it had a cracked head cover. he said he would start it once in a while it would start but
rough. He said he welded it and put it back together. Then it would just crank no sign of it wanting
to fire up. So he put an add on FB for free. Every thing works sept the motor.
So I took it. Me and my 20 yr old son looked at it not ever worked on one before. He squeezed
the bulb to many time it stated dripping from the carbs. But it backed fired through the
exhaust like it was out of time and only on one cylinder. #1 has 30 PSI which I know is low.
#2 has 140 PSI #3 has 130 PSI by just cranking the motor. All the same time limit.
I don't hear air escaping any where. So I'm starting to think maybe piston rings?
So if it is that how does one do the repair on the piston. I bought a new head
cover already and gasket. It don't look hard but still I looked all over but the right place for info on
it. Never found it. I bought a service book on it but it is not here sense it was Yesterday I bought
it.
I want to check the water pump also sense he said it is what caused the crack.
So if some one has a URL for my needs It be for welcomed
I heard I have to Powerhead has to be removed from exhaust housing.----Flywheel and electrical stuff removed.----Block has to be split.
If so how to's to do that. A URL to how to's any kinda help.
and boat with trailer.
He said it had a cracked head cover. he said he would start it once in a while it would start but
rough. He said he welded it and put it back together. Then it would just crank no sign of it wanting
to fire up. So he put an add on FB for free. Every thing works sept the motor.
So I took it. Me and my 20 yr old son looked at it not ever worked on one before. He squeezed
the bulb to many time it stated dripping from the carbs. But it backed fired through the
exhaust like it was out of time and only on one cylinder. #1 has 30 PSI which I know is low.
#2 has 140 PSI #3 has 130 PSI by just cranking the motor. All the same time limit.
I don't hear air escaping any where. So I'm starting to think maybe piston rings?
So if it is that how does one do the repair on the piston. I bought a new head
cover already and gasket. It don't look hard but still I looked all over but the right place for info on
it. Never found it. I bought a service book on it but it is not here sense it was Yesterday I bought
it.
I want to check the water pump also sense he said it is what caused the crack.
So if some one has a URL for my needs It be for welcomed
I heard I have to Powerhead has to be removed from exhaust housing.----Flywheel and electrical stuff removed.----Block has to be split.
If so how to's to do that. A URL to how to's any kinda help.