Need Help quick!

[reptikes]

I just got my bike (2004 Honda CRF450R)back today after getting new piston/rings, valves, carb cleaned, ect. Well i couldn't start the da*n thing. I had to catch it in gear to get it to start initially, i let it idle for about 5 minutes and shut it down and im now able to kick start it. I started it back up and noticed the head pipe was GLOWING FIRE RED from where it comes out the motor to about 14' inches out! And it was back firing on decel. What should i have it jetted at? Im near Pittsburgh (elevation wise). And i don't know if it matters when jetting but i have a lot of other stuff done to the bike too.

Wiseco - high compression piston 12.5:1
Dr. D - full exhaust
Scary Fast - Power Now Power Plate
Boyesen - Quick Shot
Boyesen - A.P.C. and impeller

So again wondering what i should be jetted at ? Is there an Air/Fuel Mixture screw that needs adjusted? and why is so much of the pipe red.

[cdrookie]

red headpipe and backfiring on decell are signs of lean carb jetting. alot of the newer 4pokes headpipes glow though, usually don't notice it till it's dark out.


but 14' inches back is a good piece to still be glowing.

[JR3]

just bump ur main up some expecially with a the **** u have just bump the main up and go bigger on the pilot and thatll make it easier to start also

[hondariderdylan]

i would say just keep bumping up your jetting until it quits being hard to start and ungodly hot

do you have a high-flow air filter on it?

[LTandRaptorider]

I wondered what that red streak in the woods was! :p

Yes, you def need to rejet. And although I'm not familiar with the CRF450, there has to be an air/fuel adjustment screw. If it's on the airbox side of the slide, it adjusts the air mix. If the screw is on the engine intake side, it adjusts the fuel mix. I am used to the airbox side, so I will use that reference. If the screw needs turned out more than 2.5 turns, means a bigger pilot jet is needed. Less than 1.5 turns out, means a smaller pilot jet needed. This is checked with the engine at idle. Start with the screw 1.5/1.75 turns out. Turning the screw in both directions until the engine just starts to stumble. Between those two points is where you want the air screw. The main jet you prob wanna get the next 3-4 sizes up from what you have in it now. Best way to check this is after warming the engine up, run the bike a short distance, hit the kill switch while still at full throttle and then remove the plug and check the plug color. Sounds like right now your plug is probably fairly white. Light brown is what you're looking for. Black of course is too rich. To save money you could buy a main jet 2 sizes larger than you have now, do the plug check to see how it is. But I figure with weather changes, never hurts to have extra mains around. And now for my disclaimer. If any of this info is not accurate, or backwards... It's late and I've had no alcohol. :p

[reptikes]

Thanks Guys. And i can't find an air/fuel screw!?

[reptikes]

Thanks again, i bumped up the pilot to a #48 and it solved everything. And i found the Air/fuel screw.