Speed + de restrict!
 

Hi all
I swear my XTR is getting slower!! anybody else heard of anything like this?
i have fitted aftermarket exhausts, however i think it has become slower since they were fitted, do i need to re jet?

nearly time to de restrict the beast...whats it like full power?? heard theyre pretty nippy!

thanks a lot!

Hi!

Have you recently dropped your bike with engine running?

DNA stage 1 & 2 filters & a fuel mod will wake up your XTR big time.

Not sure what you mean by full power, we have a 74 rear wheel HP XTX on the forum (Kriss007) now that is full power.

The bike is fuel injected, i.e. no carburettor, and no carb means no jet either so you can't re jet. Wait til you have it de restricted and then you will enjoy the full power, from then on as Kev said you can change the filters with Hi-Flo ones (DNA stage 1 and stage 2) and your bike will go like the clappers.

The simple thing about fuel injection is the more air you let in and/or the less restricted the exhaust is, you will need to adjust the fuel as well. This is where the "kevmod" comes in. It drops the registered temperature on your air intake sensor with a variable resistor in order to richen up the fuel going in for any given throttle position.

Without the extra fuel your bike will be leaner and may actually feel slower, mainly due to the throttle not being as responsive. As I found on my non lambda 04XTR Yamaha run their injection pretty lean as standard to meet emissions laws and even with the standard exhaust and airbox, you can use the richer mixture.

Powercommanders etc programme the fuel more accurately throughout the rev range but "Kevmods" do a good basic job, especially where its needed, in the low and mid revs.

Brilliant thanks for the responce guys! its all making sence, I will definatley be looking at the Kev mods when the restrictor is out, cant wait to unleash the beast!