I just put the BG exhuast and pipes on and made the jetting changes to spec as directed by Big Gun. I also put 104 octane in and when I took it out for a run in low 20's temp (very cold) it sputtered a little toward the top of mid range and bottom of top end. Any suggestions. I read that I should be using the fuel from the pumps becuase the motor was designed for opt performance with that octane. ANY SUGGESTIONS!!!!!!!!!!!!! How can I determine what is wrong???

Thanks and Merry Christmas everyone.

 

Make sure it warmed up for about 5 minutes if it is real cold. Also I would say that maybe it could be too rich, do you know how to read your plug and see?

 

From what you are saying the octane has no bearing on the problem. The 3/4 to full throttle range is the main jet circuit. Without a reading on the plug I'd guess you are running lean possibly due to the cold temp. Like the other post said , read your plug after a high speed run. That's the sure way to determine your jetting

 

I've just been running pump gas in my Raptor with no problems, and unless you changed the compression you probably don't need the 104 octane. Also my YZ400f motocross bike hates running on race gas, so I'm not sure if the Raptor is similar. Since you are running at 20 degrees and if the Raptor is popping at high revs, I would say you are lean. Is the suggested jetting for 60-70 degrees or 20 degrees?

 

I have just installed head pipes and silencer on my raptor.I let it sit and idle till it warmed up and noticed the pipes were glowing red!

What would cause this a lean condition I am guessing? It is not moving it is up on blocks with no front end on it.(Ordered new A-Arms)

Help would be appreciated.