Reply to thread

First post here on the forum, as i found your thread by way of searching 1999 YZ250 jetting/carb stuff. I also have a new to me 1999 YZ250 and it sounds like our bikes were cut of the same cloth. My YZ runs like a champ from mid to top, but is exceedingly rich off the bottom. It burbles and basically runs terrible under minimal throttle, then cleans out after 1/4 throttle or so. I have leaned out the pilot to what I consider a dangerously lean jet, with no luck. It has good compresison, and passed a leakdown test so unlikely it's the crank seals.

Since my bike was leaking gas and the float setting was seemingly unresponsive, I attempted to replace the needle & seat. I then found that the seat is actually pressed into the carb body. And unfortunately the carb body is no longer available. So Yay...

I just picked up a carb from a 2001, which is reputed to be a great upgrade. It's a PWK Air Striker and is common swap on CR250s.

Anyhoo, i'll let you know if this is my silver bullet or not. HOpe you get yours running perfect!