Hey all, just picked up a 2012 KLX250S yesterday, just under 7000 miles on it. It has a full fmf exhaust on it and was ridden nearly completely on road by an older gentleman. I'm fairly familiar with carbs, but honestly I just need to have this thing reliable, and starting this week. I know I can rip the carbs apart and check the jetting....but I'd rather not. Any other way to tell if it's too lean?

 

When my bike had stock jetting, full throttle on the highway at night produced a red hot header. Jetted it did not glow.

 

I'll have to try that then. It's pretty cold here now (Wisconsin) so this will be fun haha

 

If you don't have any instrumentation to check, pull the enrichener (choke) **** out while running steady throttle, if it picks up a bit the jetting is lean. The enrichener adds a bit of fuel making the mix slightly richer. Another way is to run steady throttle for a mile or so, then pull in the clutch and hit the kill switch to take a plug reading, takes some time running to get a decent burn pattern on the plug. Want a nice tan. Black is rich white is lean. Look up spark plug reading for a pictorial representation.

 

So I just took it for a ride, afterwards i pulled the choke out, she went up to about 4500 rpm. So lean as all he** then huh?

 

 

I'd say so.

 

This is 2019 - things are different now - the above plug reading information is correct as long as you are burning straight gasoline.

In this century, if you are getting your gas out of the same pumps that cars are using, you are burning E10 - E15, and the above plug reading information does not apply - worse yet is that the above plug information will lead you in the wrong direction !

 

that's a good point. I haven't even needed to fuel the thing yet, I run straight gas whenever I can. I just put a new plug in tonight, tomorrow I'll get fuel into it and after a tank or so take another look at it. I bought a handful of jets (only $3 apiece) so I've got them if needed.

 

too "lean" if it falls over.... ha ha