Still LauCo
New Member
- Sep 20, 2007
- 408
- Boat Info
- 300 Sundancer 1996
- Engines
- Twin 5.7L EFI Alpha One Drives
Good Afternoon,
(1996 300DA/twin 5.7L Mercs, 600hrs)
I'm completely lost. Here is the story-
I was headed out on a trip, boat running great. Went to get fuel, leaving the gas dock my port engine was hard to start... it took about 3 separate 10 second uses of the starter for it to fire, which has never happened before.
Went to get up on plane, and it felt sluggish. I then heard a loud knocking from the port side rear. I assumed it was the outdrive. I brought it home on one engine, and checked everything I know to check. At idle, and without load it seems to run just fine at all RPM ranges. Under load, the knocking seems severe. I also noticed black smoke coming from the outdrive.
I brought it (on the other engine) to a repair facility, and told them I suspected something in the outdrive, explained the symptoms etc... They pulled the boat, the outdrive checked out fine. They put the boat back in the water to do further diagnosis. It was determined that the port side fuel injector was only getting about 19lbs PSI, when it should get over 30. They replaced the fuel pump/fuel cooler, and advised to change the oil and plugs, because a rich fuel condition was causing the black smoke out of the exhaust, so I had them do both. (Both engines were tuned up less than 50 hrs ago, and the oil was fresh, but what's a little extra maintenance?)
They sea trialed the boat today, and the knock is still there. they are now telling me i need a new long block, and suspect that a piston wrist pin might have gave out.
So now I am out the $1200 for the pump, cooler, oil change and plugs, and they are telling me it didn't fix the problem. Furthermore, they are telling me that I need a new long block.
I am tempted to have the boat put back together, use it as a dock queen for the rest of the year (we love our marina, and can use our dinghy for buzzing around) and deal with this over the winter.
Any thoughts would be appreciated, mechanical stuff is not my forte.
Thanks!
(1996 300DA/twin 5.7L Mercs, 600hrs)
I'm completely lost. Here is the story-
I was headed out on a trip, boat running great. Went to get fuel, leaving the gas dock my port engine was hard to start... it took about 3 separate 10 second uses of the starter for it to fire, which has never happened before.
Went to get up on plane, and it felt sluggish. I then heard a loud knocking from the port side rear. I assumed it was the outdrive. I brought it home on one engine, and checked everything I know to check. At idle, and without load it seems to run just fine at all RPM ranges. Under load, the knocking seems severe. I also noticed black smoke coming from the outdrive.
I brought it (on the other engine) to a repair facility, and told them I suspected something in the outdrive, explained the symptoms etc... They pulled the boat, the outdrive checked out fine. They put the boat back in the water to do further diagnosis. It was determined that the port side fuel injector was only getting about 19lbs PSI, when it should get over 30. They replaced the fuel pump/fuel cooler, and advised to change the oil and plugs, because a rich fuel condition was causing the black smoke out of the exhaust, so I had them do both. (Both engines were tuned up less than 50 hrs ago, and the oil was fresh, but what's a little extra maintenance?)
They sea trialed the boat today, and the knock is still there. they are now telling me i need a new long block, and suspect that a piston wrist pin might have gave out.
So now I am out the $1200 for the pump, cooler, oil change and plugs, and they are telling me it didn't fix the problem. Furthermore, they are telling me that I need a new long block.
I am tempted to have the boat put back together, use it as a dock queen for the rest of the year (we love our marina, and can use our dinghy for buzzing around) and deal with this over the winter.
Any thoughts would be appreciated, mechanical stuff is not my forte.
Thanks!