I cracked my motor about a month ago so I got a really good deal on a salvaged title F4i and took the motor from that bike and swapped it into mine. Wishing now I would've just bought a good running motor cause that bike was sitting outside for over a year with mud for oil. Anyway, when I put that motor in my bike I put new plugs, swapped the coil packs, throttle bodies & FPR from my motor onto it. Started the bike up and it ran fine so rode to my friends house to go make wheelies but as soon as I stopped the bike stalled out. Went to go start it and it wouldn't start. When the bike cooled down it would start. I heard a whole bunch of **** to try so I started trying things. I swapped out the stator & the starter motor. I swapped the regulator/rectifier, switched relays and the computer and still nothing. The bike starts fine when its cold but once it warms up it wont turn over. Here's a quick vid of what its doing. This is 10 minutes after I finished putting in my old starter motor which is in good working order. When I put the starter motor in the bike started up fine so I was hoping that solved the problem. I let it warm up and went to start it again and it sounded fine but the third time I tried to start it up it didn't sound too good and that's when I got the camera. Haven't went back to the garage but I think it'll start right up now Oh its not the battery either coz I took my friends battery and put it on my bike and my bike still did the same thing and we took my battery and put it on his bike and his started right up with no problems. I visually checked all wiring and didnt see anything out of the ordinary. Any helps appreciated. All I wanna do is ride my 2wheeler again. Its been over a month and I'm going ****in nuts

http://www.youtube.com/watch?v=4pZ7YJCzMLg

 

Anyone???

 

sorry, the rectifier would have been my guess.

 

I know you swapped batteries, but that really looks like a bad battery. Will it start with a jump once its warmed up? If so, it is more than likely the battery. I would hook the battery charger up to it and crank it over then when it warm to see if it makes any difference.

Even swapping batteries may notlead to the correct answer. Is it the same bike? If not, some bikes require less cca to start. If your buddies bike requires less than yours, then your weak battery would work in his bike, but his would not work in yours..

I would do the jump test, if it works, get yourself a new battery.

 

Tried that today. As soon as it wouldnt start put the charger on it and nothing. Oh and my friend has the same exact bike so **** lol.

 

there can only be a few things to cause this. most of which you have already done.

The only other thing i can think of is your timing is off. Without the timing just right, it will start hard or not all when its warm. the engine will fight itself as it spins over. the engine is basically firing too soon and locks the rotation of the crank. It will still run fine once its going, but a warmed up engine tends to preignite easier than a cold one.

Also, I would do a quick test on the relay. Next time it wont start, jump the relay with a screwdiver and see it spins over. If it does, then you havea weak relay. I know you replaced it, but I'd still check it.

Other than those, I have no idea.

 

I was going to say timing as well. It still seems extremely slow turning over,mine spins up a heck of a lot faster. I would check all of your ground connections too.

 

How can I test the timing coz that sounds exactly like whats going on. I replaced both relays and that didnt help anything. I can try to jump the relays but since I replaced them both I dont see how that would be the problem. I'm about to pick up a new motor which sucks but at least I made back all my money from parting out the bike and now I just have a crap motor. I was thinking of having my old motor rebuilt using the block from the bad motor since thats the part that cracked on mine. Actually I dont know if its called the block that cracked on my motor but I'll take pics to see if you guys think it'll be worth it. Probably not coz I think it would be cheaper to buy a new motor then repair my old one but who knows???

 

Been there done that Checked the ground connections, swapped out everything i could possibly think of and dont know what else to try. One of my boys is a bike mechanic and I showed him the video since he lives kinda far from me. He told me try this try that etc etc etc and after I told him I tried everything he said that the motor is probably shot to ish. Something about the heat expanding the piston which stops the motor from turning over or something of that nature. He said he could do a compression test on it but if the motors screwed I'd have to have it rebuilt which I think would cost more money then buying a new to me used motor. Arghhhh I just wanna ride my 2 wheeler already. Im going on 6 weeks I think without riding and its driving me nuts already

 

Just an update. Put the first motor in and had the problems listed above. Swapped some stuff related to the motor - starter motor rectifier, stator, etc etc etc and nothing so I assumed the motor was toast since it was the only thing new to the equation. So I buy a motor from a friend of mine - put it in the bike and DAM - same exact thing is happening. At that point the only thing that had not been changed was the wiring harness. Swapped the wiring harness and fixed. YAY but I wish I wouldve swapped the harness before swapping another motor :banghead: Thanks to everyone for your help and suggestions.