I need jetting suggestions for a 2000 400ex with k&n air filter and yoshimura standard complete exhaust with a stock engine. right now i have a #175 main and the clip droped 1 notch on the jet needle (4th notch down) and #50 slow jet and the head pipe will glow red after idleing a few minutes. also bogs with air box lid on full throtle any body out there have the same setup or seen this? thanks.

 

I have the same exact setup but I am running the needle on the 3rd notch a 170 jet and have holes in my air box lid. It runs quite well from what I have seen so far (pipe has only been on for a day. Did you have a problem getting the head pipe not to leak at the head?

 

I work at a dealership and i asked yoshimura what to jett my 2001 400ex at ...They suggested 160-162 main and 1 click down on the needle and DONT mess with the pilot jett...I have yet to buy my pipe but will so soon ....HOPE this helps .....

 

i have a full titanium yoshi pipe w/k&n filter and i am up to a 170 main,i didn't mess with any other adj.i started with a 160 but is was running real hot.when you are jetted to lean it will run real hot,when to rich it will stall out.hope it helps.

 

I had the problem with the pipe turning red and over reving...Forgot ot put a gasket on my carb after I rejetted hehe..fixed it very soon.