HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
Jeff_Magnusson

Auto decompression on a 426

10 posts in this topic

Does anyone know if the 250f cam is similar to the 426f exhaust cam. I have checked on Yamaha of Troys website and the two models I could look at showed almost an identical part number between the two bikes. The only difference was in the first three numbers which looked like they were changed only because of the year. If the 250f cams are the same it would be a cake walk to install auto decompression onto a 426 using a 03' 250f cam. I did not believe that the 450f and 426f cams would be the same since it appears they have changed the head significantly. Any Ideas?

Share this post


Link to post
Share on other sites

Aftermarket cam makers could copy the yamaha decompression design, pay the royalties and sell thousands of 'em for the 400 thru 426 mounts.

C'mon american aftermarket people, MAKE OUR DAY!

Share this post


Link to post
Share on other sites

I'm trying to figure this one out myself... a dealer who frequents this board is getting a 03 450 cam to see if it is possible with that one, or if the 250 cam is the way to go... at the moment, the best chance seems to be the 250 cam... If I find anymore out, I will let everyone know... (once I get my cam ordered!) There has been talk of Yamaha stopping ordering of existing 03 250 cam parts... check out the 250F forums for more details...

David

Share this post


Link to post
Share on other sites

REAL MAN don't need autodeco, nor electric start ... you pu$i$ :)

Just kiding! :D

I wander how come no one said this yet ???

Another thing is that you cannot broke what you do not have (gee my english sucks) I love my xr for not having radiators!

Share this post


Link to post
Share on other sites

Hey sabin, maybe these guys should just waight untill there bike has done 140,000ks, there compression will be starting to get a bit low by then and they wont have to worry about changing camshafts. :):D

Share this post


Link to post
Share on other sites

Did you just pic 140000km or you have some real data?

My bike is about 10 000 and I have to adjust valves, I was wandering if I also change rings, as my engine is out of the frame for winter inspection.

Share this post


Link to post
Share on other sites

Just picked it, if your bike isn't using oil or blowing smoke i wouldn't worry about the rings. i have learnt of a 426 that has done 18,000ks motor untouched.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0