Volvo Penta 3.0L problems...

[fluidmotion]

I just got a boat and it has a Volvo Penta SX (3.0L).

The boat has been sitting for quite some time (3 years before I got it this year) and I have been brought it out about 15 times this year. After receving the boat, I changed the spark plugs, oil, added fresh gas and seafoam, and rebuilt the carbs.

The problem I am having is that sometimes the motor has problems starting. This happens probably once every 20-30 times I start the boat. It never happens when the motor is cold (at least not yet). Last time it happened, it was after a sudden stop.

The motor does start but after cranking it many times. There are not visible obstructions at the prop or the water cooling intakes.

Some other odd things are that the motor sometimes just stops running, even when I am at WOT.

The timing is probably off slightly because at a certain rpm, the motor seems to want to die.

Can Timing cause the motor to not start only sometimes? I have yet to check compression and probably replace the fuel filter. Is there anything else I should check for?

[overdalimit]

I understand that you rebuilt the carb(s)? This is an i/o, correct? Sounds like a float sticking kind of problem. Retarded timing can make an engine hard starting and sluggish but it would not cause it to just die. Float sticking open would cause a flooding condition that would cause it to crank alot before it finally fires up. Water in the fuel would make it die at WOT and then not start back up easily. Old fuel lines breaking down and particles getting into the carbs could cause this. Rust too. varnish from the tank breaking loose? Electric fuel pump cutting out intermittantly? Fuel filter plugging up? The other place to look is at the wiring/ignition system. The tach could be bad and shorting out the ignition system. Could be the connection or wiring in the distributor (perhaps there is rodent damage to the wiring that shorts out every once in a while? This is what I would start with.