1995 GTS misfire?

[kbb587]

I'm new to the forum, and can't believe how packed it is with great info & knowledge. I currently have a problem with my 1995 GTS w/587. The first time out this year, I was cruising across the lake at full speed for about 10 minutes, when the machine suddenly lost power. I was no longer able to stay on plane, and I had to feather the throttle to get it back to shore. On the trailer, the machine fires right up, but it seems to not be firing right, and almost sounds / feels like it's hitting a rev limiter. I have about 115 lbs of compression on each cylinder cold), which I've heard isn't great, but should still run fine. The mechanic at the local marina thought it was an mpem problem, but before I spend the dollars for a new one, I thought I would tap into the knowledge on this sight for advice.

 

[deepdiver]

On these engines always consider a fuel blockage problem, especially if you haven't changed the old grey lines. Lots of info on that in other threads.

 

[kbb587]

Thanks for the quick response. My GTS does indeed have the gray fuel lines, so I will replace them. Do you know if the carb on the GTS has an internal fuel filter? I know there is an external on up by the gas tank.

 

[deepdiver]

All the Mikuni carbs, yours also have an internal filter. Replacing the lines is to keep it from happening in the future. The problem usually is the internal filters in the carb, just behind the fuel pump. I have two carbs so had to do both. I assume you have checked and claenaed the external. There is a lot of info re this problem and fix. Search fuel line, carburetor, surging to find them. Hope that helps. May not be your problem but worth doing anyway.