Okay, I have a 04' z400 with full white brothers exhaust, and pro design custom air-intake. My main jet is a 165 right now (no airbox lid). Seems to be running just fine.

I'm getting my bored-out piston back from wiseco this week (12:2:1 compression, 92mm), and my brother is going to help me put a hotcam stage 1 intake cam in this weekend. My question to you is...do I need to make any jetting changes? I emailed both companies, but probably won't hear back for awhile. I think some jets came with the intake cam, but I'm not positive. Anyways, should I leave the main jet alone, do I need to adjust the needle at all? Any and all feedback appreciated.

 

I'm thinking you will since it's a higher compression. You'll also need to run premium, i think that is good enough. I'm sure someone will chime in on what exactly to do. Alba also has application- specific jet sets.

 

if its an oversized piston your going to need more fuel and with the cam you need more fuel too, i would say go up to a 175 and see how it runs, as for the needle clip, hold the quad at 1/2 throttle, and if it runs fine and smooth, its fine.

 

Cool tip on the needle. Hate to walk on original topic but, wene you hold it at half throttle to test needle, do you mean under load or in nuetral? [img]i/expressions/face-icon-small-confused.gif[/img]

 

I've actually been running on premium now. Now I think I'll run on premium/race mix.

I talked to a guy from HotCams yesterday, and he basicaly said that....

New Cam - should run bike richer
New Piston - should run lean

Haven't heard back from wiseco just yet, but it'll probably be more of the same. I'm going to try it with the 165 and see what happens. Can always go up from there.

 

I'd try it now just to see how it runs, but I'd richen until its too rich and drop one size... Better Richer than leaner, You don't want to cook that piston dont you ??

The intake cam will let more air come in the combustion chamber so you should need to go richer...
And with the high-comp piston, 11:1 would be the maximum to run on premium gas, but 12:1 and premium/race mix is good.

just my $0.02

 

thanks for the advice, this has helped.