hi new member to this site, need some help with a hot start issue, i have an 2001 f4i, starts up fine when its cold, but after riding 30 minutes or so and turn off the bike, when i go to start it back up again. it doesn't want to start. i hear the fuel injectors "whine" or prep. then when i hit the ignition button it doesn't turn over or click and yes im in neutral and kickstand is up as and i have the bank angle sensor bypassed since its a stunt bike. after it cools down it will start up fine normally. Ive already replaced my Air Intake temperature sensor, Manifold Air Pressure (MAP) sensor, kickstand sensor, and about to replace my coolant temperature sensor. Not sure if its my thermostat or water pump acting up. If anyone has had this problem before please let me know, i hate not knowing whats wrong with my bike and its annoying having to wait for my bike to cool down before i can start it up again.

 

check the electrical expansion can cause a loss of connection to a stretched wire... other than that idea anything else might want a expert owner

 

How old is the battery? You might put it on a charger.

 

where is the electrical expansion can located at? and idk if its the battery, battery is a couple years old i know that, i never replaced it from the guy i bought it off of. but the battery holds a charge fine. its just when the bike itself is hot it doesn't want to turn over but as soon as it cools down it starts right up with no hesitation. i tried calling a few mechanics and telling them what happened and one said that it could be my starter motor could be bad. getting frustrated cause i cant find the problem!! haha any additional help would be greatly appreciated! thank you!

 

Sound electrical if it total don't turn over....

This is a tough one. Without more information, especially about the condition of the bike, its hard to say. Could be as simple as the spark plugs needing regapped or it could be something much more complicated like wear in the engine or carbs. Try the easy things first. do a tune up, change fuel and air filters (if you havent recently). Do a compression check on the engine both when cold and when hot to rule out an internal problem with the engine. You could have a bad gasket somewhere along the intake tract or a leaky header gasket which only leaks when hot. You can use smoke from a cigarette to find a leak along the intake - the smoke will get sucked in. A leaky header gasket will usually leave telltale scorch marks.

 

After some thoughts.......and heat causes resistance in wires, connections etc.

you may want to loosen, clean and tighten the battery cables at both ends.

Also, check the starter relay? It may be failing when Hot.

It's 80-90% electrical because it's not turning over when hot. If it cranks but don't fire up...different story.

 

I meant check the electrical for expansion...sorry i type crappy sometimes. You are going just look all the wiring over. Cause if you find one issue you might as well fix all electrical wear and not have to worry about it again. Good luck...you take your time you will locate it.. Check places wires might rub..all connections..with the Battery removed use electrical contact cleaner. Check for tight wires ect. You will find it

 

could it possibly be my neutral switch acting up? before i went to stunt the other day i removed my steering stabilizer and put my tachometer back on to kinda monitor the temp. i noticed the neutral light acts up when im riding or at higher temperatures. i was riding at about 40mph and dropped the bike into neutral. after i did that i noticed my neutral light flickering and when come to a red light id be in neutral but the bike wouldn't register on the tach that its in neutral and i have the clutch fully disengaged so i know that it is in neutral. could that possibly be the problem? since the bike wont register that its in neutral could be the possibility to why its not starting when hot? when i turn the bike off when its hot and leave it in neutral it wont show on the tach that its in neutral until the bike cools off then the neutral light will come on.

 

If the neutral light flickers, definitely...either loose, dirty, connection bad....it should be located near the gear box and shifter....check it

 

thats what i was about to do i have a repair manual i downloaded for ten dollars, if anyone wants a copy lt me know i can probably email you a repaid manual if need be, but yes the neutral light is flickering, i ordered a new one today and hoping this is the cause of my troubles cause its been going on way to long! lol do i need to drain my oil or coolant if i replace the neutral switch?