Dupli paint and 400ex headers and jetting

[unitednations]

So i painted my headers with high head dupli-color paint and after it dried i started the bike and omg the paint bubbled and smelled burnt. It smoked like mad. Its 1200 degree paint. The headers get around 900 at idle. Any one have any ideas about this?

Also my spark plug i can not tell if the bike is lean or not. The color is like a whiteish tanish mix. there are no deposits on it. I did like 13 plug checks and get this.


HFM PIPE
11:compression
40, 3rd notch, 168 jets

[ballerchaos]

correct me if im wrong, but it sounds like you need to be jetted, your probably running to rich cuaseing your bike to run hotter. my buddy had a simular problem where he was running so hot it actually melted his plastic closest to his exhuast. we jetted the carb propperly and it runs alot cooler, and and a hell of alot better.

[bherriman]

Running rich would actually make it run cooler (unless you somehow have a diesel 400 ex then more gas would equal more heat lol) A lean condition would make it run hot, but if the paint is rated at 1200 degress and you said your head pipe only gets to 900 my guess is the surface wasn't prepped correctly or it wasn't allowed enough time to dry. The paint should be able to handle 900 degrees.

[aDviSol2y]

My father in law painted his stock 300ex headers with the same paint. It did the same thing. He let the chit dry for 2 days. Its the paint. It sucks!

[CJM]

Grill paint works 100x better..

[JOHNDOE83]

My "440ex" runs a 600 degree header temp at idle and after a ride....900 is high!

Maybe jetting would help?

[unitednations]

Well 900 revving it going no where. Its around 600 after riding. Normal exhaust gas is 1250, so i do not think 900 is that high. Thats why the pipes glow red at night.


Idk the jetting was fine i thought. idk why it changed when i didnt do anything to the bike.

[JOHNDOE83]

pipes shouldnt ever glow, mine only did when it was to lean.

What temp does your cylinder run?

[unitednations]

Yes they do. Ask anyone. It did when it was stock. The headers glow at night. The cylinder is around 200-250

[oliver1650]

I've never seen any of my quads or bike with glowing headers at night. The only time I've ever heard of anything doing is when it's lean.

[JOHNDOE83]

Originally posted by unitednations
Yes they do. Ask anyone. It did when it was stock. The headers glow at night. The cylinder is around 200-250

They do when they are to lean, the factory doesnt actually jet the bikes they all get a ballpark jetting range depending on the area they are being sold and they run on the lean side so they arent rich when you buy it, supposedly "440s run hotter" and mine does not cause its jetted properly and my headers dont glow even at night.

200-250 is good, I wonder why your exhaust gets so high?

A whiteish plug is a lean plug even if theres tan, if you bump up the jetting it may get a lil cooler?

The paint probaly wasnt any good, Ive bought bad cans of paint before ,one works great then the other doesnt dry and bubbles.?

Grill paint is the way to go.

[unitednations]

Yeah it might be a little on the lean side. I had a 42 jet in it and that was way to rich,

But maybe its not my pilot jet. But then again the quad is idling when the temps get so high.

Maybe i should change the needle clip position? This is really bugging me. I had it rich for a while now its to lean wtf :(

[sc400ex_rider]

use the grill paint its no joke. mine held up over 2 years.

[unitednations]

as for the paint ill try that. but for the jetting.... idk what to try now

[mjc400ex]

It's probably bubbling because the paint is not letting the heat dissipate from the pipes. Painting a pipe is similar to wrapping it with insulation. The pipe would normally dissipate some heat through the metal air interface on the head pipe. With the paint on it all of that heat stays in the pipe and it is probably getting up to the 1200 degrees the paint breaks down at.

[dalejiw25]

If you say that a 42 pilot is way too rich you have other problems. I've put 42 pilots in completely stock bikes and had them do nothing but run better and start easier, In fact I have a 42 pilot in my stock 300ex. IMO you are way lean on the pilot side. You sure you're not confusing rich with lean ???? I'd try a 45 pilot and see how she runs. Your needle has no affect on Idle. Hell I'm runnin a 440 Stroker and my Headers never Glow.