red headpipe

[northeast400]

I am running A full HMF system and a 142 Dynojet main. it seem to run fine with the air lid on. I took off the lid and installed a Sparks key. I took it for a rip and the header started glowing red!! should those mods make that big of a difference?

[khen]

Airbox lid off will definitly lean it out.

[400exr]

Originally posted by khen
Airbox lid off will definitly lean it out.

Ya, sounds like your running lean, does it backfire?

[4TraxRider]

The airbox lid taken off will lean out the engine, causing heat, and the degree key, correct me if I'm wrong, also makes an engine run hotter. So if both mods are done at the same time it will produce a lot of extra heat.

[44oEX]

A 142 is way lean, 148 is the stock size

Just go bigger on the main.

[hondarider2006]

Originally posted by 44oEX
A 142 is way lean, 148 is the stock size

Just go bigger on the main.

yup

[toby400ex]

A dynojet 142 is bigger than a stock 148 jet. With the mods and altitude he has its what dyno jet says to use, but thats with the lid on not off. I think with the lid off u go up to dj165

[northeast400]

I will try a 165dj hope I did not damage it

[cals400ex]

i bet a 165 dynojet is too big. many on here run the 142-146 dynojet with pipes. does the header glow around half throttle, at idle, or at full throttle?? this will help us determine if it is the main, needle or pilot jet that is lean. also, dynojets and keihin jets are NOT the same.

[MOFO]

if you just took the lid off, I would go up to the next couple sizes and see what happens. No sense in us trying to guess for you. Best bet is to buy a few larger...

[northeast400]

it started to glow while I was doing burnouts at full throttle (long story)

[44oEX]

Then it's probably cause no air was hiting it so it just got to hot.
Mind did the same thing when I did burnout.

[TGW_400ex]

Goto the HMF site they tell you wha to run and its way bigger than that

[cals400ex]

dynojets are not the same a keihin jets. if it glows at full throttle, i would go up one size at a time on the main until it doesn't glow, then stop there. if it glows at 1/2 throttle, i would raise the needle i position. if it glows at idle, back the fuel skrew out in small increments until it doesn't glow. if you have to go out more than around 2.5 or 3 turns, get the next size bigger pilot jet. good luck

[cals400ex]

by the way, hmf's jetting specs are too dang big in my opinion. your bike will run fine with what they tell you to jet with, it just won't be as fast as what it could be.