Mods - Is order important
Posted February 04, 2005 - 08:52 PM
Posted February 04, 2005 - 09:26 PM
Posted February 04, 2005 - 09:30 PM
Yamaha built it the way they did because California told them to, not because their engineers wanted it that way. To see what the engineers wanted, look at the YZ.
If you can pull the exhaust restrictor and grey wire, you can remove and replace, or remove, cut, and replace the throttle stop screw.
I'd say that the throttle stop screw will have the biggest impact. Stock, you only have 2/3 ro 3/4 throttle.
The grey wire and exhaust restrictor will definitely help. Unfortunately, you can't move the jet needle on the '05 WR... the only option is to rejet. The JD kit isn't cheap, but it gets very good reviews.
Posted February 05, 2005 - 06:20 AM
Posted February 05, 2005 - 09:24 AM
The 450 screw is a couple of MM shorter than the 250 screw, but either will work in either bike (I'm running the 450 screw in my 250)
Overall length, including the bolt head, should be between 22 and 25mm.. IOTW, stand the screw "up" on a table and the tip will be 22 to 25mm above the surface.
If it is too short, the slide will hit the carb cover and eventually crack it. If it's too long, you get less than 100% throttle. The shorter 450 screw does NOT allow my 250 slide to hit.
The hard way is to pull the air filter, look into the carb with a mirror, have a friend pin the throttle, then back out the screw until the slide is exactly 100% open. At that point, measure the length of the exposed threads and cut exactly that much off of the tip.
This is a little more difficult because you're looking into the airbox on the left side and the screw if on the right