Hi.I have just purchased a 2007 te250. It has a 300 Atena kit fitted along with high flow filter and Husky competition tail pipe. It had been standing for several years and the guy I purchased it from had the carb apart to clean it and replace some jets. Before Using the bike I have checked the valve settings and replace the ap diaphram and o rings in the carb. Although it now starts It is difficult to get a good idle and if I snap the throttle it bogs and dies, If I roll the throttle on it builds revs with no problems, Current jetting is Main 180, pilot 50, and leak 70 fuel screw 1 1/2 turns out. Needle set on 4th groove.does anyone know where to buy an adjustable fuel screw here in the uk. I have tried increasing fuel screw to 2 turns but this seems to make little difference. Any advice on jetting would be a great help.
You are going to have to do a few things...the "standing for several years" poses some problems. First thing I would do is order a new pilots and mains the same and one up and down from what you have now - then toss the jets in there. I only know FCR's well on 4S - but you really need to clean everything extremely well. Check all the little orifices and blow them clean with a proper air tool. Make sure you get it all fitted properly (no air leaks etc) and start with your baseline jetting (with new jets) and see what you have. If you still are having major stumble and idle issues, drop the pilot down 5 and try getting a baseline again. You have a bunch of unknowns - the biggest of which is that carb that sat. Jetting for big bores are usually pretty close to original specs - your biggest enemy now is some little hunk caught up in a carb passage someplace. We did this several years back and wound up tossing the carb for a $150 part out carb and that fixed it overnight. Hopefully new jets and a proper cleaning will get you on the right path.
