[Ler's434z]

Hey everyone i just recently rebuilt my 04 z400 ported and polished head bbk full yoshi exhaust i don't even have 2hrs on the motor yet. I still have the stock card on it but i put a 60 main jet in it no air box lid either by thr way but when i took out the at night the other night i noticed the head pipe was glowing cherry red i hadn't noticed it b4 . What do u think could be the problem to much air or what and what should i do. Besides not ride it any and all help would be appreciated

 

[CFM]

The glowing exhaust is one of those topics that gets some pretty wild answers. At idle, sitting still, it's normal to have a little glow, especially at a faster idle speed. I don't think that's what you're dealing with, but people will say it's rich, lean, valves need set, and all kinds of things, but it's important to know, that in some situations like that, something that's tuned perfect will do it.

If your pipe is constantly glowing, odds are you are a little lean on your carb settings. Have you put a jet kit in this thing? It didn't sound like it. People do get by just changing the main to something near a 170, and sticking an extra shim under the needle, but in my opinion, it's improper. The stock needle just doesn't have the right taper to be run without the air box restriction. All that said, it is normal to see some glowing of the pipe at night, under a load. If it's red, I don't worry. If it's Orange to yellow, it's more of a concern.

My recommendation is to get a jet kit. Not that ebay junk either. My preference is dynojet. It comes with the needle you need, and an assortment of jets, and instructions. The one thing they don't include that I like to do as well is a 25 pilot. Most of the time, the 25 makes for a better idle setting, and a smoother transition from the pilot to the needle.

 

[jetmech25]

I think you mean a 160 main, which is probably a little small. The main only works at the top half of the rpm band, so it does nothing at idle. Your pilot is what works at idle and you’ll need a 25 and a better needle than stock.