1989 Force 125 falls on it's face at 2500 RPM

[bunder]

I have a 1989 bayliner with a Force 125 outboard. This thing is driving me crazy. I've had it into two different mechanics and neither one of them was able to figure out what the problem is. It has great compression. The carbs have been rebuilt the stater tests OK. The fulepump has been rebuilt. It starts and idles great but starts to cut out around 2000 and drops flat on it's face at 2500. I have pulled plug wires one at a time at idle there is a more noticeable difference on cylinders 3 and 4, but at 2000 the change is about the same across all 4. I have run it up until it stalls at 2500 and then pulled the carb bowls both were full. I switched coils around no change. I'm at a loss and have lost almost my entire summer. Any advice would be greatly appreciated.<br /><br />Thanks,

 

[clanton]

Re: 1989 Force 125 falls on it's face at 2500 RPM

Connect timimg light, run engine until misfires accurs, look at light if it is ignition you will see the light blink. If ignition you need meter to check. It may be a broke wire/s on timer, commom problem see other post this engine.

 

[sony2001]

Re: 1989 Force 125 falls on it's face at 2500 RPM

bunder it sounds as though at 2000 rpm one cylinder quits then at 2500 rpm a second one quits. With two out it indicates that the same CDunit {switchbox} might be quitting on you. It might be the one operating the weaker cylinders at idle.<br />In my Force I prefer the Champion L76V plugs.

 

[bunder]

Re: 1989 Force 125 falls on it's face at 2500 RPM

Thanks for the advice. Where is the timing adjustment on the force 125? I checked the output on each of the plug wires they all came out the same. It dosen't look like a lack of spark, but possibly a timing problem.