3.0 drivin me crazy!!

[lodough780]

I have a 1988 winner 1700 w/mercruiser 3.0 that I have owned for 4 years. It has performed well until my last trip out last year.
While running along at 4000 rpms the motor just started sputtering and losing power and wouldn't open up past half throttle. I winterized the boat and parked her until spring.This year I have done everything that I know to do and it still wont run right. Can anyone help me figure this thing out???
Heres what all I have done so far:
New plugs
New wires
new condensor
new points
rebuilt Mercarb
cleaned fuel pump bowl
set dwell@32 degrees
adjusted timing to 2 degrees BTC
There looks like there is plenty of gas going through the carb while running and there isnt any fuel backflowing to the carb on the clear line that is connected to the fuel pump.
Right now my boating days are filled with frustration and wrenches. Any help would greatly be appreciated.
The only thing I can think to do next is check the valves or do a compression test.

 

[Don S]

Re: 3.0 drivin me crazy!!

Sounds like fuel starvation to me, here is some tests you can do to find out why.

http://forums.iboats.com/showthread.php?t=167561

 

[lodough780]

Re: 3.0 drivin me crazy!!

Thanks for the info, I wasn't aware of those testing proceedures.

 

[lodough780]

Re: 3.0 drivin me crazy!!

After readjusting rebuilt mercarb float level and changing my plugs I went to the lake for a spin.
After 4 hours of running good and pulling several people on skis and tubes the motor started doing the same thing all over again. In the 4 hour time span it used a full tank of gas.
I pulled the plugs when I got home and they were black as coal with soot. WHat do I need to adjust on the carb now???
Has anyone had the same problem before???