Jetting a sparks x-6 exhaust

[Hotdog]

I added a sparks exhasust and when i start and let idle and after about a minute the header is so hot you cant even touch it. I think that maybe my pilot jet is too small (42). Any thoughts on what the jetting should be?

[Knips178]

Your header will get to hot to touch no matter how you jet it. A stock 400ex right off the showroom will heat the header up past what you would want to touch in a matter of a couple minutes. What about when you run it? does it bog or feel weak?

[Hotdog]

it seems to have decent throttle response. i really haven't had it running very long. the heat scared my. its been last fall since it was started. i did a complete rebuild of the quad over winter.

i will try riding it tonight.

thanks