Hi All, I just bought a 2001 DS650 and have a couple of questions still to resolve even after searching the forums. First of all, here is the setup: Big Gun Race exhaust, Woods CDI box, jetting unknown, K&N air filter and prefilter, 3 holes drilled in airbox cover, other than that the bike seems to be stock. I've replaced the cooling fan ( it was dead). I started the bike tonight after I got the fan back in to see if it would come on- to check the thermostatic swith. I used a jumper to check fan operation and it works fine. However when the bike was idling, I noticed that the exhaust pipes at the head prior to the collector were glowing red. The bike had only been idling for about two minutes when I noticed it. I figure this is not normal. I did a search on mixture and found a post that said that a rich mixture would cause this. I was thinking that a lean mixture would cause it to run hot. Which is it??? Also I started thinking that maybe an exhaust leak at the head might also cause it. Is a gasket required on the exhaust pipes. I had the pipes off when cleaning up the bike and I did not notice any gaskets in there. I tried to richen the idle mixture ( center screw on the bottom of the carb...I think???) but it did not have an effect. I don't know what jets are in it but the PO said that the jets were replaced at the dealer when the pipe was installed. Any help would be appreciated.

 

Actually, it could be lean or fat. A lean mixture will lead to increased exhaust gas temps, while running rich can send unburnt fuel into the exhaust. There, it can burn and light your pipes up.

I know that doesn't help you much, but you might as well just mess with it until you get things figured out.

 

When I had my stock pipe on, it would glow red, I could only notice this at night, I was told it was normal, what does your spark plug look like after idle ? It may be to lean