100hp?

[Nieskes]

You are going to have to run a boost bottle to achieve

that kind of power.

[camatv]

if you spray paint your pipes black that helps out a lot too. just make sure they are mounted on the bike when you do it the more overspray the more areodynamic it can get

[jaspersbanshee]

You may have got a better response if you would have told us what was done to your bike now and then ask what was a good hp upgrade for the riding you do. To answer your question lol yes 100hp out of a 421 is easy but if you are riding real trails then that is a waste of a motor.

Thanks for your input!!! 100 hp is goal, not a necessity. If you don;t have goals life is worthless. Right now I have stock stroke, .040 over, fmf fatty w/ powercore 2 silencers, +4 timing, cool head w/ 20 cc domes, boyesen ss carbon fiber reeds, reed spacers, stock carbs w/ 320 mains 32.5 pilots (TORS eliminated). I built it from ground up, paint, sandblast, everything in engine and tranny, etc. So, I understand alot. (but alot i havent experienced). Had it dynoed last spring. 55 hp 35 lb/ft hp peaked at 4500 and held it to 9500. Its not a racer, but not bad for what it is! Just like anything else, got used to it and now i need more. Theres my life in a nutshell. I appreciate any help or comments.

[jbooker82]

Dune Ported 4mill (or a 4mill Serval) with CPI pipes, Keihin PWK 33's will make for a fun ride. Dont get a wrapped up in HP numbers. I would consider the only way to hit 100 HP is with a drag port or cylinder that uses a drag port durations. The more hp you want the higher and narrower the power delivery is. You can't get more power for free, it is going to cost you bottom end and midragne.