02 YZ250 Kickstart assy. mod (R & D).

I've decided to start a little blog to help owners of 2002-up Yamaha YZ250 Dirt bikes. This was inspired by multiple ideas coming from a great ATV, Dirt Bike forum, ThumperTalk. This is the first picture of the bike I bought for a small amount of money, it will be modified and new pictures will appear during winter and as I go.





Short Story:
I bought a 2002 YZ250 dirt bike with the kickstart assembly shaft snapped inside the case, leaving a portion of the shaft remaing and huge cracks in my crankcase cover. I decided to browse the web for similar issues and found a great thread on the Thumpertalk website. Many members had the same problem and one member got me thinking while he mentionned using pre-02 parts ...

Reasearch :
I've pushed that idea a bit more and decided to give the idea a try. From the micros, I searched for parts and figured they could probably fit with minimal modifications. I ordered a 2002 Yamaha YZ250 Crankcase Cover and a 1999 Yamaha YZ250 Kickstart assembly from the popular ebay motors.



Comparing parts :

Identical specifications are (Go!)

• Starter Gear is the same size, same # of teeth


• White plastic is identical


• Spring is identical


• Lenght is identical


• 2002 Kickstart lever bolt fits in the 1999 shaft (shown in picture)

Picture :

• Left part is the 1999 Yamaha YZ250 starter assembly kit


• Left part has the 2002 kickstart lever bolt to prove it fits perfectly


• Both parts are the same lenght

Parts that will need some modification :

• 1999 shaft is 2mm bigger. Splines will need to fit the 2002 kickstart lever


• The hole in the casing will need ajustment (2mm bigger so 1999 shaft can fit)


• External Rubber bushing will need to be fit (might need to buy a 1999 rubber bushing)

Next Steps :

• Talk to my contact that has a machine shop


• Have them do the modifications


• Add comments and pictures to this blog