I have a 05 yfz 450 and I was recently riding when the bike just completely shut down. I thought it was a solenoid seeing the fact that someone butchered the old wiring. So I rewired the correct solenoid and no the starter is just freely spinning and not engaging. So when I figured I'd order a new one I notice I also am getting no spark. Even if I take the coil off the starter will still spin as if wanting to engage if I hit the start button. It will still do the same even if I remove the cdi box. So I'm completely stumped on if I should replace all three or what could be the actual problem. Any info helps thank you

 

When you say coil are you talking starter coil?

 

The coil plug that plugs in the spark plug

 

If you don't have them you should get a multimeter and a schematic, for the no spark you going to need to check the resistance at the ignition coil, pickup coil, rotational coil, and all wires between the those, the switches, and the cdi.

for the starter that sounds odd I would have to hear what it's doing before I could help.

 

Any luck?