Ok. I just bought a 96 F3 that was in pretty bad shape cosmetically.. So i took all of the farings off. Cleaned the bike up repainted the frame baught a new gas tank that i had to clean out and installed it. I also took the exhaust and headers off repainted and reinstalled them. New air filter changed the oil and fixed an oil leak on the stator. Bike ran ok before i got the new gas tank. But after installing the new gas tank the bike started up just fine ran for well for about 5 min, So i took it out for a ride around the block. Then it started to bogg down, the pitch of the exhaust got deep and i lost power. After a few seconds of that with me giving it more gas it would come out of it and exhaust sounded nice and high and the power was back. Then a few minutes later it would bogg down again and would knock at lower RPM's. I got it back to the garage, baught some gas stabilizer, heat, and injector cleaner (thinking i had some bad gas with some residue from the cleaning). Put them in the tank and it ran fine the next day on a 15 min ride on some back streets.. So i took it out a few days later on the highway and it bogged down again going about 60. Same change in pitch of the exhaust and same lose of power and still knocking at low RPMs. Only this time it didnt change back to normal and it will only start and keep running with the choke on all the way or if i give it gas keeping it around 3000 rpms.. I ended up having a buddy come pick me up with his truck. So then i changed the spark plugs and fuel filter thinking i had clogged the filter and or had bad spark. The old spark plugs werent bad a little black around the thread but mostly brown. After that still no change. Some other moods i had done to the bike while cleaning it was relocating the rectifier to the inside of the frame along with the ingnition modual and fuel cut relay. I also put LED brake lights and turn signals on the rear and flush mount turn signals and running lights on the front. I also saudered i broken wire that was going to the conection on the throtle possition sensor. I have the haynes manual and have checked for proper wireing and it all checks out good. Now i am at a loss for what to do next. Do i need to remove the carbs and clean them out or could it be the fuel pump. What else could it possibly be? Any ideas or adivce would be greatly appreciated..

 

Hey Steward, to check the fule pump, follow the tube from the gas tank to the fuel pump, and disconnect the tube that goes out from the fuel pump to the engine. Place the outgoing tube into a bucket. Start the bike, if fuel sprays fairly well, the pump works. However, I believe it may be a carb problem, take them apart and clean them, if that doesnt work, post back and we'll see.

 

does it start up any more? that does sound like your fuel pump is going bad but do what burning in flames said and check it out!

 

Steward, Just a thought, my manual says to check the fuel cap breather pipe on California models, that suffer from these symptoms. (yeah it gives a bucket load of other causes as well)
It causes a vacuum effect between the flow of fuel in the tank to the fuel pump, Turn it off, and it corrects itself, till the pressure builds up again after you start the bike. Can't tell you wot it look like as my manual doesn't specify, but it should be obvious if you have that type.

 

Thanks for the advice i wont be able to work on it for a few days. After reading some of the earlier posts with people who have similar symptoms im going to first check the fuel cut off modual, then the fuel pump ( hopefully it is one of those two cause i really dont want to have to take the carbs apart) So much work with so little of summer ridding left i was reading in the manual and maybe i put the header exhaust on a little off. Maybe that is causeing some back preasure in the heads and cylinders causeing it to run bad. So i guess i will recheck that as well. If i do have to rebuild the carbs which jet rebuild kit do you guys recomend also should i upgrade to stage II jets?

Thanks for the advice so far. This forum has been a big help reading all of the other posts. I will be sure and post some pics of the finished project from start to finish..

 

fixed the problem it turned out to be the conection for the fuel pump at the control modual. Unfortunatly i found this out after cleaning the carbs twice and putting everything back together twice. It was the yellow and blue wire that controled the fuel cut off switch which in turn made the fuel pump not work. so i re soldered the wire and conection to the control modual and walla runs great even better than before. thanx for the help everyone.

 

thnx 4 the follow up, glad your up n runnin