4mil jetting

[jst854]

I finally figured out that my CDI box was junk and now the engine will actually rev out. It has the following mods, 34mm mikuni's, CPI inframes, 4mm long rod, cool head around 145 psi, very aggreasive port, vf3 reeds.

Here is my problem, The bike runs awesome in 5th and 6th gear, but will not rev out in any other gear. It seems like the higher the gear is the more it will rev out. 1st and 2nd will barely get past half throttle. I have 520's in for main and 75 for the pilot and the clip is in the middle position. I was going to try leaning out the needle and see where that takes me. You guys have any ideas?

[sleeper06]

75 pilots are off I would try 30s,how does it idle is it dull.I just built a 4mil drag port ended up with 420 mains,32.5 pilot,needle second clip from top with rocket pipes.Im not too familiar with mikunis but this guy had them allready so i made them work

[jst854]

75 pilots are off I would try 30s,how does it idle is it dull.I just built a 4mil drag port ended up with 420 mains,32.5 pilot,needle second clip from top with rocket pipes.Im not too familiar with mikunis but this guy had them allready so i made them work

 

30's sound really lean for the pilot, isnt stock 27.5? Regardless I will start going down on the pilot and see where that takes me. Why would it rev out clean in 5th and 6th but not any other gear though?

It idles ok, the air screws are about 1.5 turns out. It will load up after a while of idling and you have to rev it to clean it out, but isnt that how most drag bikes are?

Edited September 23, 2010 by jst854

[jst854]

I dropped the pilots down to 50's and it seems to be running better. I can get it to rev out in all the gears if I bring the throttle up gradually instead of just holding it pinned. Is that a indication of it being lean or rich?

[sleeper06]

my shit was crisp,drop the mains a lil