JD Jetting O-ring size

Does anyone happen to know what the size of the big o-ring that came with the JD kit? I accidentally dropped it and can't find it.

I used a #78. Instead of trying to stretch it on, which is hard. Remove the adjustment screw and slip it on. Then reset the screw to where it was(count turns or measure the gap with a slide caliper before removal), stock mine was set at 2.75mm where I left it. Not my pic but shows the gap. There is also talk posted on this board about a wide open throttle gap, on the 37mm carb it isn't an issue from what I've seen, but you can check it. Let the 450 guys worry about that one..aptimingclosedthrottle250x.jpg

In the 450 page it has a link to the AP mod I think it reccomends a 5/16" o ring

Most bike shops have an assortment of O-rings you can select from. I never had the JD kit, I just looked thru what my dealer had on hand and selected 3 or 4 to try of different diameters and different thicknesses so as to have different elasticities, and then picked one that fit suggly across the AP link lever without being too difficult to stretch into place. I made no adjustments of any kind, and it works awesome--immediate response from right off idle to way up into the rev range.

Thanks guys I'll try some of those

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