Hi All,
I'm a newbie to this forum and to boat ownership. Like a lot of folks, I know automotive well, but am trying to get to grips with the differences in boating.
I recently bought a 1990 Four Winns 190 Freedom with the GM V6 based OMC 4.3 in it. I've done a partial engine rebuild (lifters, con rod bearings, gaskets etc.). Also put all new ignition (coil, distributor, wires and plugs) in, replaced both water pumps and fuel filter, but still have an issue.
At cold, it starts first turn and runs great. I get it up to about 3,500 rpm on the lake, can run for 10-15 minutes, no problems. Oil pressure and temperature bang on normal for the whole period. Then, oil pressure starts to drop, revs drop and it almost goes into a limp mode, but if I drop it to idle, it cuts out and won't restart until it's cool, then it's absolutely fine again, until the same thing happens. Thought it might be temp, fuel or ignition related, hence all the new parts, but no luck. I've had it on the bellows for over 1/2 hr out of the water and can't get it to re-create the problem.
Has anyone else experienced? I replaced the oil pressure sensor as well yesterday, so it's not that. Could it be the oil pump?
Any good ideas would be very welcome. Starting to pull my hair out in frustration.
Thanks.
I'm a newbie to this forum and to boat ownership. Like a lot of folks, I know automotive well, but am trying to get to grips with the differences in boating.
I recently bought a 1990 Four Winns 190 Freedom with the GM V6 based OMC 4.3 in it. I've done a partial engine rebuild (lifters, con rod bearings, gaskets etc.). Also put all new ignition (coil, distributor, wires and plugs) in, replaced both water pumps and fuel filter, but still have an issue.
At cold, it starts first turn and runs great. I get it up to about 3,500 rpm on the lake, can run for 10-15 minutes, no problems. Oil pressure and temperature bang on normal for the whole period. Then, oil pressure starts to drop, revs drop and it almost goes into a limp mode, but if I drop it to idle, it cuts out and won't restart until it's cool, then it's absolutely fine again, until the same thing happens. Thought it might be temp, fuel or ignition related, hence all the new parts, but no luck. I've had it on the bellows for over 1/2 hr out of the water and can't get it to re-create the problem.
Has anyone else experienced? I replaced the oil pressure sensor as well yesterday, so it's not that. Could it be the oil pump?
Any good ideas would be very welcome. Starting to pull my hair out in frustration.
Thanks.