Friend bought a used 04 Raptor 660 from a kid that he took to the dunes last year. When the kid had it, it wasn't running so he took it to a Yamaha dealer that ordered a new top end but was too busy to install it so the kid took the bike and parts to a guy that used to work for the dealer and he put it back together. The thing would not start by using the starter, but it will start by being towed and runs great until the rpms are dropped to almost idle and it dies and won't start again with the starter but will being towed. It did that at the dunes last year and is still doing it now. Any ideas on what would cause this? Thanks.

 

try timing

 

Yeah I'd listen to nikates, he has a 97 mph raptor. LOL

 

you know what you can suck go ahead

 

Check your ground between the battery and frame.
A friend of mine hade the same problem after his rebiuld.
He didnt hook up the ground.

 

Got some more info, the bike ran and started good all day on the first trip and then late afternoon started doing its thing so I think timing and ground should be ok but we will check.

 

And when turning it over with the starter there is no spark at all.

 

Is that no spark with a new plug or the old plug?

 

Tried it with both and even put in a new plug and same thing, had to tow.

 

This probably is not it but check the spark plug boot. It has a screw built into it so it can twist itself into the coil wire. The screw in mine broke in half and the spark would not jump across the gap when attempting to fire up using the starter.

You should be able to tell by trying to lightly tug the boot off the coil wire.


/Jon