416 over heating

[TURBO400]

JUST GOT DONE REBUILD OF MY NOW 416 10.8:1 WIT A HOTCAM , CHOKE REMOVED AND AIR BOX LID OFF. STARTED HER UP FOR THE FIRST TIME AND NO LONGER THAN A MINUTE LATER THE HEAD PIPES WERE GLOWING RED.

i have a 154 dynojet in it what should i be using? figured i was running too lean

[BlasterEaten250]

what octane gas are you using?

[2004exrider]

check jetting and the spark plug color, but other wise its normal for the 400ex's head pipe to glow due to the thin metal its made of.

Jimmy

[luvmyex]

it is?:huh

[Crazy Diamond]

I'm not to sure on that! I'd have to say its too lean.

[aviator4]

Yeah, sorry, glowing headpipes is never "normal" - check your plug and your jetting. Sounds like you're running lean. Did you bring your jets up a size or two (or three) after you did the 416 upgrade?

[TURBO400]

i have a k&n filter and a fmf pipe, i put the 94 octane gas from sunoco. i am going to get a 42 pilot but what size main should i use and what brand?

[aviator4]

I'd probably start at a 156 and see where you are. It doesn't really matter what brand of jets you get. Mikuni jets are readily available. Keep in mind that if you get "dynojet" jets, they will be made for a dynojet needle, and won't work with the stock needle. So don't buy someones half-used kit.

[2004exrider]

Originally posted by aviator4
Yeah, sorry, glowing headpipes is never "normal" - check your plug and your jetting. Sounds like you're running lean. Did you bring your jets up a size or two (or three) after you did the 416 upgrade?

Just for the hell of it, take yours out at night and ride it for a while (until its at operating temperature), then stop and turn your lights off and look at the head pipe i guarentee that they will glow a little.
http://www.exriders.com/vbb/showthread.php?s=&threadid=145898&highlight=glowing

Jimmy

[aviator4]

take a look at his post again. It says:


NO LONGER THAN A MINUTE LATER THE HEAD PIPES WERE GLOWING RED

THIS is a sign of a lean condition.

We love to ride at night on the dunes for hours at a time climbing, fast trails, etc.. and take several breaks during the ride to rest and check the bikes. We have a total of 5 400EX'es, a 250EX, a DS 650, a Raptor 660R and whever else people bring with our group... oh and several small 110's.

NONE of their pipes EVER glow red. Even in 90+ temps outside and riding HARD for over an hour.

Any time we see a set of hearders glowing, we take the bike back and put in on the dyno... sure enough it's running lean. If you keep the jetting set up correctly, you shouldn't exceed the temp limits of the metal (which is what a glowing pipe is doing)

Glowing pipes, IMHO are a bad thing, it means you're heating and cooling the pipe to temperatures that can make it extremely brittle.

This may be true for some thin, single wall pipes like the stock pipe, but I've never seen an aftermarket pipe glow when the bike is truned properly.

[Colby@C&DRacing]

Originally posted by aviator4
I'd probably start at a 156 and see where you are. It doesn't really matter what brand of jets you get. Mikuni jets are readily available. Keep in mind that if you get "dynojet" jets, they will be made for a dynojet needle, and won't work with the stock needle. So don't buy someones half-used kit.

Mikuni jets will not work in keihin carb........... If you are running a jet kit you will need to use the supplied main jets with the supplied needle.

[aviator4]

Sorry. Meant Kehin. I had just gotten of the phone with a guy talking about his Z400... guess I hadn't switched back into "Honda" mode. LOL.

[TURBO400]

the guy i bought the quad from supposedly had a dynojet kit but the main jet is a 170 and we measured the hole and it is correct but for dynojet its a 154 so i don't know what this guy put in there. anyway to tell what type needle?

[sandspanker]

Go back to the stock needle those dyno jet kits are junk,never had any luck with them. the jets for one thing are not big enuff. i have a 416 stock needle 42 pilot and a 162 main @ sea level. if I let it sit at idle long enuff the head pipe will start to glow @ a high idle.if you just got it back together and you were breaking in the cam,between 1-2 thousand rpm that will deff. get the head pipe glowing when breaking in the engine.always make sure you have a big fan blowing on the engine to keep the temp down. and for the guy who's pipe never gets red you need to ride hard or stay home. lol jk

[aviator4]

Umm... take a look at my signature, get a good idea of what kind of 400 I ride... it 'aint your grandma's bike. LOL.

There are a few people on here that will attest to how hard I ride usually.

I have the added benefit of having "free reign" on a DynoJet dyno... my bike is always tuned just right... I was just speaking of my experiences.

[TURBO400]

just got done puttin a 185 main and the 42 pilot, the headers lit up again but i put a fan in front of the quad, still orange and still running hot as hell. my clutch cable is gone. i atleast got done the first break-in but still don't feel right wit the way it runs so dam hot. any suggestions pleez?????

[ZeroLogic]

This may sound stupid but check and see if your oil filter is in the right way. A shop installed my oil filter backwards and my engine kept on over-heating and ruined the engine and what not.