xp carb update?

[mphfreak]

Aguy on the hill last week told me he got a carb update and his sled really woke up in the mids. Has anyone else heard about this?

 

[LRD]

Sounds like he may have the needle shimmed up to richen the mid range which if its to lean to begin with would probably liven it up a bit and give better throttle response. One clip move on a mikuni needle is generally about 40 thou which can be to much sometimes. There is a needle shim kit called "5/20 Shim Kit" and is part number #220-715 for $8.95 from HPE here http://www.hiperf.com/

The shims are washers consisting of 10 thou, 20 thou, and 30 thou allowing you to raise the needle 1/4, 1/2 or 3/4 position. The only tricky part is when you put the washer under the needle clip (to raise it and make richer) the little hook clamp that is holding the needle in place with the allen head bolt can be hard to get back in place. I have found locking the throttle wide open with the slides pulled all the way to the top is the easiest for messing with the needles on the XP flatslides.

Good Luck

 

[PJ-Hunter]

Sounds like he may have the needle shimmed up to richen the mid range which if its to lean to begin with would probably liven it up a bit and give better throttle response. One clip move on a mikuni needle is generally about 40 thou which can be to much sometimes. There is a needle shim kit called "5/20 Shim Kit" and is part number #220-715 for $8.95 from HPE here http://www.hiperf.com/

The shims are washers consisting of 10 thou, 20 thou, and 30 thou allowing you to raise the needle 1/4, 1/2 or 3/4 position. The only tricky part is when you put the washer under the needle clip (to raise it and make richer) the little hook clamp that is holding the needle in place with the allen head bolt can be hard to get back in place. I have found locking the throttle wide open with the slides pulled all the way to the top is the easiest for messing with the needles on the XP flatslides.

Good Luck

From what I've heard, the XP carbs don't have clip positions on the needle. Is this true? I have heard that you just have to shim the needle using the nylon bushing.

 

[cableguy]

Correct about no adjustment clips. I added a nylon bushing after I put the Terra alps head on it. Runs nice and crisp.

 

[spring snow hero]

holy cow they really did take every little bit of extra weight out of those sleds.....yikes

 

[LRD]

holy cow they really did take every little bit of extra weight out of those sleds.....yikes

Only one clip position you can blame on EPA not on weight loss.

Good Luck