My bike sometimes starts and sometimes will not. It always tries but it seems like it just will not turn over sometimes. It happens when it is hot or cold with no reason. I have never been stuck, I just wait a few seconds and try again and it starts. Any ideas???

Watch the link. Hayabusa Poor Starting Stalling Poor Running FIXED SOLUTION

there is a sensor on ur bike sometimes under the seat or around the battery box on the back of the sensor (always has two) it will look like plastic if that pastic looks like it melted they are the problem

Hi, When you shift do you have high RPMs. Try lowering RPMs when you shift.
Also you said it gets warm. Try using a different oil (heavier oil). Hope that helps.

try changing and using the correct oil in the clutch section of the transmission or transmission proper

It's electrical problem, it seems like something is draining your bike's battery, not letting enough current to go to starter for a strong engine cranking, I suspect there might be a short circuit within the ignition switch and/or wiring, as you said the bike keeps running even with the key out.

I've got a 2006 and just found this while surfing around...


Realistically, diagnosing the problem behind a bike that won't start, can be a frustrating experience, as there are many potential problems that can create the same symptoms. Here are a couple of guidelines to help determine the root of a "labored" starting problem, and by "labored", we mean that the starter motor kicks in and attemps to turn the engine over, but either can't get it over the "hump", or does so with a lot more effort than usual.

If your battery is over two years old, and you CONSISTENTLY have a labored start, then the first suspect will be the battery.

If she starts cold with no problems, but CONSISTENTLY has labored starting while hot, then the charging system should be checked. A grounding rectifier can actually discharge your battery while you ride. The battery can somewhat recover while sitting, so it may well start the bike while its cold, but then not be able to start it after only a few miles of riding.

If everything on the bike seems to be in perfect order, and you OCCASIONALLY have a labored start, or no-start, for no apparent reason, and with no perceived pattern, then very likely, the rear decomp cam is loose. A good test for this is to place the bike in second or third gear when it won't crank, and push it backwards a few inches while in gear, then try again. If it starts then, you definately have a loose rear cam. Pushing the bike backwards while in gear moves the rear piston back off its compression stroke enough to give the system a running start at it when you push the button. This will only happen when the rear cylinder stops on its compression stroke. Therefore, it seems impossible to predict when it won't start. Might be cold, might be hot, might only happen once today, but maybe three times tomorrow...This occasional no-start is the prime indicator that the problem lies with the rear decomp cam. (If the front cam were out of adjustment, it would NEVER start properly, as both cams would then be off their specs.)

---Quoted from http://www.moccsplace.com/images/decomp/decomp.htm

check pulse coil generator system...sometimes hot oil leaks onto the pickups and then the ohm readings aren't right...check ohm readings on these pulse coils only when not working. i had this problem and it would always push start no matter what...have you tried to push start it....try that first...pretty good chance if it does start your pulse coils are getting to hot.

Check the igintion switch tracing the wiring for the pump..there could be a problem there....a contact problem.
Not a bad idea to spray WD-40 to the contact point of the switch.
Hope this helps!

hav u done a tuneup-chec plug wires n batt-wat about an inspect of wiring thru bike-they can hide alot-giv carbs a physical too

If you did indeed overheat the engine to the point that is stuck, you would probably know it by the antifreeze being poured all over the ground. The bike would be really hot just sitting on it. It would smell like antifreeze and just smell hot.. I know, smell hot? but an engine that has been ran to hot has a pretty distinctive hot smell... It doesnt sound like an overheating situation if none of the above happened. A bike that is overheating will begin to loose power before it stops. LIke lacuna said, everything inside of the engine will start to expand from the heat and the piston will stick in the cylinder. Most of the time when this happens, the bike will cool off and restart. But, usually with problems. Warped or cracked head, cracked block, broken piston rings. These engines are aluminum and dont like to be overheated and warp really easy. If the engine is really hot, it will not turn over until it cools down enough. Im not saying it couldnt have overheated and then restarted without any problems, its happened before, but just not likely. But, if this is the case, take lacunas advice and change all of the fluids. Your oil will be nasty. Maybe get ahold of the previous owner and see if it has had any probems. It kinda sounds electrical to me. as long as the above overheating signs didnt happen. If you dont think it was overheating and it happens again, try to push start the bike to see if the engine turns over. even putting the bike in second or third gear just see if you can move the bike back and forth. If nothing else, you'll at least know its not locked up.