Still Problems

[Forbin]

Rebuilt carb, ballast resistor, new fuel line, water fuel sep, tune up. This is what just happened.

STarted it and is seemed really rough at idle, shook the boat. Drove out and boat kept shaking. I gave it gas and it went up on plane then is just slowed right down. I threw it in nuetral and gave it gas. It reved up to about 6000 rpm in nuetral but then just slowed right down, backfired once and stopped with out me touching the throttle. Started riight back up but when put in gear the boat shakes with black smoke coming out of it. Took it back to marina at a very slow pace while it went in and out of smooth to rough cruizing. It would be smooth cruizing then all the sudden shaking and rough and then smooth etc etc.

Whats wrong with this boat.

 

[airdvr1227]

Re: Still Problems

What are we working on?

 

[Forbin]

Re: Still Problems

Sorry, 17' 1976 crestliner OMC Straight 6.

 

[proshadetree]

Re: Still Problems

The black smoke indicates flooding condition. Who preformed the tuneup and why? Who built the carb and why? Has a compression reading been preformed on this engine?

 

[Forbin]

Re: Still Problems

Ok Sorry for the delay but I had to find the work order.

I marina place did the tune up. Here is what they did:
Condenser
Point Set
Rotor
Spark Plugs
Dist Cap
Compression test on all 6 cyl. @ 165 psi
Says Replaced plug - intermittent miss.
Set Ignition Dwell and timing

So this was done in May and I have had nothing but problems. Took it in again and ever time they took it out for a test they said it ran fine for them.

When I take it out it is ****. So finally I decided to get the Carb rebuilt 2 weeks ago. Took it out Friday night and it seems ok but not like it was before I took it in in May. It had more power. Then on Saturday the shaking an dblack smoking happened and it looked as if there was unused gas coming out of the exhaust. Not much but some.

I have also replace ballast resistor, volt reg and alternator

I didn't think boat were this difficult to diagnose.

Please help

 

[Don S]

Re: Still Problems

I didn't think boat were this difficult to diagnose.

They aren't if the mechanic knows what he is doing.

So this was done in May and I have had nothing but problems. Took it in again and ever time they took it out for a test they said it ran fine for them.

Go with them on the next run. then just point and say "See, that is what I'm talking about"

After getting the boat warmed up, have you looked to make sure the choke is open? Was the idle mixture adjusted on the engine after it was rebuilt?

 

[Howard Sterndrive]

Re: Still Problems

It reved up to about 6000 rpm in nuetral but then just slowed right down

holy carp, why do people do that? - you may have bent a pushrod or one might have even sidestepped a rocker at that speed

ditto on checking the choke and things like firing order and if the distributor cap is clipped on right.... basic visual checks go a long way
then onto timing and compression check to see if 6K broke something.. the "then it slowed down" sounds like damage from overspeed