A forum for owners of Yamaha TTR250 trail and enduro bikes!

There was some question about stock jets on US models - for the record, I pulled the carb on my 2003 US model, which I'm pretty certain has never been touched, and the jets are in fact 137/50 (as Jarrah had opined) even though my manual says the pilot is 52.  I was told this bike was originally sold in Alaska, where it sat for many years (without draining the carb).  Don't know if the Alaska thing could mean a different carb set up from the factory, that doesn't seem likely.

I bought it this winter and have only had it out for real 4 times since.  After I cleaned the air filter and pipe I was having an idle speed problem, it seemed lean at idle and I couldn't adjust it, so cleaned the carb and it idles just fine now and starts without choke when warm (all settings are per manual, air intake, filter and pipe are still stock US).  The jets weren't super clogged but needed a cleaning.  It still doesn't purr at idle quite like it did with a gummed carb and filthy air filter, but I no longer have any gasp or drag when accelerating off idle and it seems to accelerate a little faster overall.  Maybe the bike just runs a little lean stock.  Or maybe I'm just fooling myself.  This is near sea level and at mild temperatures.  I plan to leave it as is for a while since most of my riding will be above 5000 feet (when the snow melts, that is), and being a little lean down here may work out ok up there.  I'll try some air flow mods in the mountains, maybe a new air filter.