Fuel System problems

I bought a pontoon baost in the winter with a 2003 Johnson 90 Hp 2-stroke on it....The first few times I took it to the lake I was very pleased with the motor and it ran excellent.....I went back over Memorial Day weekend and i noticed on friday that it was stumbling at high rpm's....Thought maybe it was bad gas....Boat did the same thing Saturday except it progressed to also cutting out a bit during takeoff and at high rpm's....On Sunday the boat ran fine for the 1st part of the day then it started cutting out almost al the time....Except for about a twenty minute period where it ran perfectly....To make matters worse I took it to a shop and they put a new fuel line on and adjusted everything....We also changed plugs....I was excited when I got to the Lake and it ran perfectly for about ten minutes then started cutting out and stuttering at high rpm's.Then it progreesed as it did over the w/ where I would have short periods of nothing wrong and then stumbling, reduced rpm,s and a sick sounding motor...The boat will not do this when in neutral when i rev the motor....Any ideas on possible problems or good repair shop in the southern/central ky area to help me solve the problem.

Thanks in avance

Have the carbs checked. If it is acting this way at high RPM, it may be starving for fuel. a good carb cleaning or possiblr rebuild could fix your problem. I'm no mechanic, but a friend of mine had a motor doing the same thing, and that is how they fixed his.

If the boat set over winter with no fuel stabelizer in the fuel tank it might have a little water in the gas tank.



DA

You did not say how old the boat was, but if it is a 2003. You may have some junk stopping up the fuel pick up in the tank. I would take the fuel line off at the tank and unscrew the pickup and check for dirt. Also if the boat is out of the water, you can remove the tank. If the tank is easy to get to, and I would empty it and save the gas check for water in the gas, if no water
filter it and use it in your vehicle clean the tank and fill with new gas. Also add some SeaFoam to help clean the system. If you still have problems than go to the carbs, you may have picked up some junk. Also check your fuel filter on the motor. Good luck.

I had the same problems a few years ago with my Triton and it turned out to be a short in the ignition switch. It wouldn't hurt to check it out.

My mechanic called me and said that they took it out and it did the same thing and they think i's a coil pack that is not working....Thanks for all the help and hopefully we've found the culprit....