I have a 07 yfz450 with a DG pipe, its been rejetted, and also has the retarted timing cam adjustment. A month ago it was running hard and then would stop cranking. I replaced the crank with a hotrod crank, and also replaced the main bearings. After all of that it will run when I pull it, but when I try the electric start its like there isn't enough juice to crank it over once it gets to the compression stroke. I have charged the battery and the voltage was at about 12.86 volts. I was wondering if I should upgrade my battery, or if my starter is worn. I have the manual to check my starter, but if i could get suggestions first, that would be great. Thanks for ur time Hopefully this bad boy gets fixed up soon

 

I would have the starter tested first.

 

alright thanks for the advice. i didn't mention that before it would start it would click like it was the solenoid by the battery but once i charged it, it did what i already said. again thanks

 

Does it start spmetimes? If so it could be the starter clutches. Even though i wouldnt think it would be being a 2007. You didnt bump up he compression hen you rebuilt it did you?
You may want to post this on yfzcentral.com and see what you get

 

i don't believe i changed the compression, unless when i did the crank it changed it some. and No it doesn't sometimes start, always just really slow to crank. like it starts to crank then as soon as the compression stroke comes up, it very slowly pushes through it. i just registered for yfzcentral.com but i am waiting to be approved for posting.

 

sorry i cant help you! good luck on yfzcentral.com

 

i finally fixed it. i upgraded to the honda cbr600rr battery, firstly. This kinda helped, but still it cranked over slowly. i then tore i down to the cams, thinking it had to be timing. well i'm sure it was because when my friend and i reassembled it, we retarded two teeth on accident. once i did, and put it back together, it fired right up. Finally my beast lives. Now for me to just break this crank in.