1988 Merc 135 V6 not ideling well

I have a 1988 SeaRay Seville with a 135HP Merc V6. It usually starts fine and runs fine all full speed but it doesn't want to run at idle. I was on the water yesterday and I could put the engine in neutral, rev it a few times then quicky put it in gear and it would be ok but if I tried to let it idle it would just die. I'm not totally, sure but it seems to be worse right after the engine has been in the up tilted position( ie while towing, or beached ) and it seems to work somewhat better after it has run for awhile. Also, one time yesterday the engine died while at idle and didn't want to start again. I eneded up squeezing the fuel line bulb a few times and it then started.

Any help would be greatly appreciated.

Mark

Re: 1988 Merc 135 V6 not ideling well

Mark, That motor has an ADI Ignition, with a stator that has low and high speed windings. Get on the CDI website and look up the troubleshooting procedure for he stator. Ohm out the low speed winding to confirm that you have spark at low speed. If you do, the carbs are likely dirty or misadjusted. Rebuild them

Re: 1988 Merc 135 V6 not ideling well

Also check the small bleed lines, if plugged or disconnected, they too will cause idle problems. My old 89 200 V6 did not like idleing very weel either, nature of the beast I think.

Re: 1988 Merc 135 V6 not ideling well

I have a 135 Black Max. I just made sure I had a good Battery so far. I hope to figure it out, but right now I agree.. Nature of the Beast.
I it possible that the floats are sticking and flooding the engine while trimmed up?

Re: 1988 Merc 135 V6 not ideling well

Thanks everyone, I'll look into the suggestions you made. I have to agree that this motor is not the best idleing motor, but through out the last 20 years it has been much better than it is now. It has also seemed to be getting worse the last year or so ( I don't use it much anymore ).

I tend to think that it's fuel related also. I'm wondering if it's a fuel pump problem. Since it seems to be worse after the engine is tilted I'm wondering the fuel is draining out and the fuel pump can't re-supply the fuel when it starts and is at idle. Since it seemed to run better after I squeezed the fuel bulb this makes sense. I wish I thought to have someone squeezing the fuel bulb while at idle to see if it helped.

Re: 1988 Merc 135 V6 not ideling well

Rebuilding the fuel pump is pretty straight forward. Directions come with the parts kit.