So i tried turning the bike on the other day and it kept cranking and cranking and not turning over. There would be a couple of loud back fires, so instead of trying to turn it on, i called it quits and decided to see if anybody else recognized this problem. Strangely the bike was running perfect a few days ago, and it hasnt been ridden since, so what could possibly have failed in that short period of time? anybody?

 

Could be valves, could be plugs, could be carbs, could be bad gas. Normally a back fire is caused by a build-up of gas or a bad fule air mixture. If the gas is building-up then it means you have little or no spark. I'd check the plugs and plug wires to start. Then check the carbs and ECU. Could be a timing problem as well ...... could be a lot of things really just gotta check it all one by one starting with the smallest thing first.

 

the same EXACT thing happened to me when i bought my F3, it ran perfect, i brought it home, a week later the same thing was happening, i bought a battery charger (it died while i was continually trying to start it) and i changed the spark plugs, it purred like a kitten after that...good luck!

 

reaplace spark plugs./ now its starts up fine! thanks for the help