mt bike is running good on low end and in the midrage but it wont pull top end... too rich on the main right?

 

Other way around usually too lean if wont pull on top but ok down low. A 39mm pwk sometimes is the other way though. Run your bike hard on top for 300 feet or so and see if plug is dark or wet (Rich), Root beer brown (right) , or light tan or grey (lean). Dont let it go needs fixed.

 

Aren't you running the stock carb with a really high main jet? You are talking about your 400 I take it??

 

try runnin it with the airbox lid off.

 

You need to do a plug check on top end. Get a new plug and go about 100yrds. Turn bike off and coast to stop and pull plug. Check your color and this will tell you. Most of the time if it sputters on top it is lean but if it just flattens out and feels weak its rich.

 

I'm talking about my 400 it has a 39pwk with a clamp on k&n, im running a way bigger main jet than everyone else on here but it ra perfect last time i took it to the dunes... not im not sure how the air temp works with jetting it was much colder when i rode it yesterday the when i jetted would that make it even more rich or the other way around? the bike is now for sale but i want to get it running right for whoever i sell it to.

 

bump

 

I'm not really sure what you are asking, but I will say this: As air gets colder, the molecules are compressed tighter together (more molecues per cubic inch). Therefore, with everything else being equal, an engine would run leaner on a colder day.

 

hmm..

 

i think its all this durn rain gumming things up