What piston should I get.

[damian600]

2005 450r

Im getting a HotCam stage-1, and I want to put a new piston in while I have my motor apart. Which one should I go with and what compression. I dont race! Just want some extra power. Also I am putting a full DASA exhaust on with a KN filter, what do I need as far as jetting goes. I was told to get a HRC needle.

[Old Head]

Well your already at 12:1 stock with a 450. and doing a cam in only the very top of the motor. If your doing it yourself make sure you get a shim kit for adjusting your valves.

[damian600]

I will be bringing it to a Honda mechanic, I just want to buy everything I need 1st, its cheaper. What does the shims do?

[440exnacsracer]

if hes a honda mechanic, he'll already have the shims...or should anyways. id throw a JE piston in it, maybe a 12.5:1. the lighter piston will allow it to rev quicker and make it a little more responsive. i would just leave the jetting to the mechanic, or better get a dyno jet jet kit for it. anyone can guess to your jetting, but without being there, it 99% of the time will be incorrect

[damian600]

The mechanic is going to do everything. What is a dyno jet?

[400eXr1d3rZ]

Originally posted by damian600
The mechanic is going to do everything. What is a dyno jet?

It's a brand of jets, Dyno Jet is the company name, I suggest staying with Keihin jets (people who make your carb), you can buy a keihin jetkit from www.jetsrus.com

I suggest getting a 12.5:1 JE piston or 13:1.

[440exnacsracer]

either/or all the jet kits will have different tapered needles and seats in the mains for more performance. ive had good luck with dyno jet, but never have tried the keihin jet kits