What happened to the pistons?

where did the the wiseco 416 piston go in the dennis kirk go? What do you guys think about that comparing it the je and the pro x. I am rebuilding my 2003 400ex this spring. I am putting a hot cam stage 1 in, I have a t-4 that is going on again and a k and n all ready. I was also wondering about jetting since I have a 138 dynojet now with the stock pilot. I live in northern wisconsin at about 2000 ft I think. I am using the stock header. This should work well for more low end right? Oh, and the 416 piston is an 87mm I think right? (maybe its not, that is why I can't find it) I searched for a while and did not find much. I am just pricing now to get everything ready. Where can I get a JE from. Hopw about the Cometioc gaskets that are 86 and 89 can the 89 mm be used for the 416? I know C&D has them so I will look into them also for everything. Thanks for all your help Steve S.

87mm is what you are looking for. I bought mine from Honda of Troy's ebay site for a fair price. I also got my stg 1 hotcam from them too. As far as brand of piston I've been a loyal Wiseco guy for 15 yrs but the JE would be the premium choice. You will want the Cometic 89mm gasket set, the 86 is just too small. The stock header is a fine choice for this combo but you will want to do the header mod to get max flow out of it. For jetting if you are running a 138 main with success then figure starting with a 148 when you get this combo together. Most likely you will be fine with the stock pilot but a bump to a 40 would not hurt. If you find any hesitation in the mid after all this then bump the needle up one clip (move the clip down on the needle).

Thanks for all the info on the rebuild. I have been looking to rebuild for so long, then I forgot where i found all my parts from. I have not been home to work on my fourwheeler. I go to college a couple hours away. Now my warranty is off so it is time to do some mods. :devil: Hopefully it will run good with the 10:1. Thanks again Steve S.