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cam+jetting = slightly less top end

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I have a 2001 400E and recently did the JD jetting, snorkel and HC intake cam. The bike now has more midrange punch and is more responsive. A friend has an identical bike but his is all stock. Before I did these mods when we raced they seemed to be pretty much even(similar weight). Now, when we race on pavement my bike seems to surge ahead of his through 2nd and 3rd, but then he starts to pull on me pretty good on the top end. It's as iff my bike stopps pulling a little early and does not want to rev quite as high as it used to.

Don't get me wrong, Im totally satisfied with the new midrange punch, but wondering if maybe my jetting is too fat on top, or if the cam trades some over-rev for midrange.

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Gearing the same? Switch bikes and try again. I don't believe you lose anything on top with the HC intake, you may gain so much in the middle that it feels that way, but I doubt it. The HC exhaust gives more on top if you were to switch to that, with just a little lose of bottom end.

As for jetting it would be the same in every gear, not just 4&5, I would think. If you are falling off on the top in every gear then it could be jetting.

We kind of need to know a little more information :cry:

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The gearing is the same.

Jetting Blue 3rd clip, 162 main

300ft elevation, 50-60 deg.

I realize that there are a thousand variables that could cause two seemingly identical bikes run differently, but mine just seems to stop pulling a little early now.

Would exhaust make an improvement on top?

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There are definate gains in responsiveness with an aftermarket FULL exhaust. The increase in head pipe size helps a lot. As for overall horsepower? Only a small gain is measured by a dyno, my specially calibrated "butt dyno" says it is more though. Stick with either a muzzy or yosh for the exhaust.

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