Super Jet How many more bores?

[SXIPro]

My SJ will need some top end lovin' over the winter. Right now it's at 735 CC. How many bores do I have left?

 

[X2Kid]

In theory I think you can go to 84mm and 754cc. There's some debate about sleeve durability at that level of over-bore - some say it's safe, others not so. There was a thread on this issue recently. The debate will probably start again!

 

[Blue]

I have seen 84.25mm but dont recommend it. We have gone to 84mm many times. We tested one in Jetmaniac's ski and got 2 years out of the motor before resleeving it.

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[cookn]

61x at 84mm makes good power too, just make sure your domes can support that bore size

 

[SXIPro]

I have seen 84.25mm but dont recommend it. We have gone to 84mm many times. We tested one in Jetmaniac's ski and got 2 years out of the motor before resleeving it.

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Thanks Blue, I've actually been PMing Chris on this, so you'll probably be the one doing this for me. My compression is quite a bit lower in my front hole than my back hole after I had some issues yesterday. It's weird, it seems to still have the same low end grunt, but I lost some top end. I don't really care about top end, so I may just ride it the rest of the season since my season is so short and then send it to you guys in the fall......unless I toast it in the interim.

I guess I need to step up to 760 domes as well.

 

[Blue]

Yes you will need 84mm domes. Just let me know when your ready and we will take care of it. Thxz

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