I have a 08 Yamaha YFZ 450.

When I go into first gear it drives by itself, like It will speed up to 10-15mph (I have a speedometer) and just drive without me pressing the throttle, When I switch to second, it'll keep driving but slow down a bit.. obviosly. My question is, Is my throttle cable to tight or something?

 

Ya either your thumb throttle is to tight or the idle set screw is way to high. That would be my guess.

 

is there any type of guide on how to adjust it

 

Here is a service manual link if that help any!
http://www.moddedraptor.com/library/...%20MANAUAL.pdf

 

thanks

 

got it to work idles great now.

 

Good deal!