mcorley122
Cadet
- Joined
- May 31, 2011
- Messages
- 11
I have a 1990 Welcraft 17? bowrider it has a Mercruser IO 3.7L 165 hp in it. I had it out on the lake this weekend, it did fine for about 10 minutes then I started to lose RPMs until about all I could do was 1000 to 1500 RPMs any thing above that it would just bog it would never die but would not speed up. I put it in neutral and it would rev to about 3000 RPMs wot and that was it. It will idle just fine and start right up every time. I had this same problem last year but it would not go over 2000 RPMs so its gotten worse. I?ve changed points, condenser, rotor, dis cap, and fuel water separator filter. I also rebuilt the carb because the accelerator pump was bad. Today I fooled with it all day had it out of the water hooked to a water hose. It will start right up like always and idles smooth, you can slowly throttle up and it accelerates smooth and quick but stops at 3000 RPMs. You can also throw the throttle hard from idle to wot and it never hesitates or misses a beat but goes flat at 3000 RPMs. While it running at 3000 RPMs you can look down carb and the butterflies are wide open. I thought it was leaning out so I went through the fuel system and found no blockage, the fuel filter in the carb was clean, the one in the fuel pump was clean, and the fuel water separator is new. I do not have a way to cheek the fuel pressure, but I ran a line in a one-pint mason jar and cranked the engine it filed it up in about 12 seconds so fuel pump is good. I also bypassed the fuel tank and fuel water separator, by running the engine off a five gallon gas can and still got the same results it also dose this regardless if the engine is hot or cold. When the engine is running at 3000 RPMs I sprayed gas down the carb, which if the engine was leaning out should have caused it to speed up but it did the opposite and would just flood. So it has to be in the ignition but what in the ignition would cause this, timing is right on 4 degrees BTDC and max advance is were it needs to be, and there is nothing binding in the mechanical advance. Could a bad coil or condenser cause this. What have I missed Please Help!!!
