I just modified my Falcon 250 with the following:

"Opened" up stock exhaust
Put in 15,5g variator rolls
Put on an open air filter, and skipped the stock air box


I havnīt opened up the carb yet and the question is what type of main jet is in the carb? And what size is it stock?

Is it "standard" kehein main jet or is there different thred-sizes??

 

stock main jet is a xxx, pilot jet is a xxx, yes they take the stanard keihin round main jet for the cv carburators. the pilot jet is a series xxx , my cn250 ran the best with a xxx main and a xx pilot with a k&n airfilter and a fnf exhaust, most any m/c shops will have these jets or you can order them on line, heres one link xxxxxx.com

 

I took apart the carb and main jet was 110 in mine. I changed to 125, and WOW what a difference. It really takes away great now!

I left the pilot as it was.

 

if it's hard starting or you need to leave the choke on until it warms up then the pilot jet needs to be larger, if it's properly jetted then you should beable to start it and drive off just like your automobile

 

Its about 0 degrees celsius cold here in Sweden and itīs starting straight away. I can drive it right of no hesitation...

Though what do You mean by leaving the choke on??? My has "auto-choke"... I canīt lever the choke manually?!?!?