[jaktheripper85]

i have a 2005 400ex with dg exhaust and i just bought a k&n air filter and the k&n powerlid which came with the main jets.... not sure which main jet would be right for me i ride in indiana and at silver lake michigan.... any suggestions?

 

[TRX2fiveO]

Welcome to the forums. if you go to Dynojets website and look up the jet kit for your 400 and open the PDF instructions you will see what is recomended I would say 170 main and a 1/2 turn out on the air screw

 

[69quadracer]

I was going to say a 165 so guess i close try 0ne size ckeck plug and go fron there black color go down whitish go up you want a good tan color on the plug.

 

[Helmut]

Welcome to the forums.

 

[elmerkit]

Welcome to the forum i suggest to open the pdf file that is posted at the dynojet website and it will sure give you ideas on how to install and choose w/c jetting to be used.

 

[jaktheripper85]

thanks for all the sugestions.... i ended up installing the filter and powerlid yesterday and took it out to see how it rode... it started up cold much easier than before and right away i noticed a huge difference in throttle response and low end power and no bog what so ever... never had it run soo good... didnt change the jet since when i bought it, it had no airbox lid and the dg exhaust soo im thinkin it has a 170 main in it already