[teselle391]

Actually its a Torx #25 bolt on the cover I believe. I too used the lg. O ring with a nice improvement over stock.

[WillCRF]

I helped a buddy down the street wake up his 450x with the JD Kit. His bike had horrible bog both off idle and on throttle. Last week we did the airbox mod, needle and main jet portion of the kit. Definitely cleaned up the bog while on throttle but there still was some hesitation coming off idle with a wack.

When I added my JD kit last year, these AP timing screw o-rings were not included so I went the Boyesen AP route. Did the job but costly compared to these o-rings. We put the larger o-ring in last night and what a difference. Actually I think it might be a bit too violent off throttle for the trails. Has anyone installed both the large and small o-ring to see if there is any difference? JD does state in the instructions the smaller 0-ring is more suitable for trail riding.

We will see how the set-up works in the woods this weekend. Might go back and try the smaller o-ring if it turns out to be too much of a beast. Does anyone else have any experience with the smaller o-ring? Also, what has been the outcome adding these o-rings with the Boyesen AP cover installed?

Will