Running way too hot

[drummer-on-a-EX]

Well I got my 10.8:1 piston(stock bore) and new hot cam installed and she fired right up and was running great, while trying to break it in I noticed the head pipe was red hot GLOWING RED HOT! some lifter noise after the glow started, turned it off, checked the oil, plenty of oil top and bottom.
pulled the valve cover off, the cam looks to be in time with the crank.
Anybody else have a similar problem or any thoughts?
Thanx

[RAPTORAZ]

Sound's like your running VERY lean. If your running a 165 main and no airbox lid (as your signature says) you're definately running lean. Mine has less cam and compression and it took a 172 main to keep it cool. Popping on deceleration and a white electrode are tell tale signs of being lean.

[drummer-on-a-EX]

Too new of a plug to read it yet and no popping on deceleration, but I will definitely re-jet before I start it up again.
Thanx

[RAPTORAZ]

If it's getting hot at a cruise, between 1/4 to 3/4 throttle, it's probably your needle setting. I'd move it up a notch when you rejet. Your always better off erring on the rich side.

[Rastus]

Sounds like jetting..


Run it for like 8 mins, let it cool. Check the plug, and get back to us.Then tell us what how much throttle you used the whole time. You can't go all over the throttle range. try it once at only idle to 1/4 throttle. Then anohter time at 1/4 to 3/4. Then a last time at 3/4 to full throttle.

Dont run it very long though. Just long enough to get a reading.

Hope this helps.

[DarkStarRacing]

most likely rejetting, let us know how eveything goes after you re jet :)

[drummer-on-a-EX]

O.K. We've re-jetted, moved the clip to the 5th position and tried a 180 jet, the plug was black as night, tried a 175 jet and it looked much better, but she is running way too hot at 3/4 throttle, I can see the header getting red hot and you can feel the the heat within seconds of start up.
Any suggestions on something I may have missed?
Thanx

[tinytim]

Mine did exactly the same thing after building in higher compression with an XR cam. For about 6 months, I did not let it idle. Increased the pilot jet (a fuel jet) setting (52 @ 2.5 turns - Keihen 38 FCR) and it went away. The main jet @ 168 was not the problem, as evidenced by how well it ran in the rest of the throttle range. Terry at Marcums pointed it out to me.

[L.Vegas400]

ok-- ive never torn apart a quad carb, so i was wonderin how many neddle setings there are, how they effect your carb and rich or lean going up or down.

[drummer-on-a-EX]

5 settings, the notch closest to the taper being the richest

try turning your air mixture screw one turn in. this should richen your mixture. if it over heating around idle it's a pilot curcuit being to lean. try the screw first. if thisdoesn't help or helps some but not enough go to a 45 pilot jet. I think you'd be better off wit a 45 to start with but i'd see if the 42 works for now.

[Bean]

pilot = if its lean here, bump it up to a 42, or mess wit airscrew

needle = if its lean here, move the clip around

main = if its lean here, bump it up to the next size or 2

[kj400]

is the header new ? i had the exact same thing happen when i did my 416 and put on the powerbong is scared the sh%t out of me to, but it ran great and by the time it was put back together it was about 12 and nice and dark so it makes it look alot worse.anyway what i was told is that the stock header is a double wall and the powerbong is a single wall so it will turn red,but once it was broken in and turned blue it never did it again. hopefully thats all it but i dont know if the wb is a single or a double, i would look into that as long as your jetted right. good luck.

[Blysster]

Did you try changing your oil? After I installed the XR cam in mine it did the same thing. The oil had allot of residue from the grease that was on the cam. I seemed to run much cooler afterwards.

Also check the clearance on your vavles again.

[EricB]

after the header is broke in, if its still running hot try some octane boost or some lead additive. or even 50/50 race fuel or something?