Xr250r no mid range or high rpms

Well I just picked up a 95 xr250r , bike runs pretty decent but it won't rev up to high rpms and kind of flat thru mid range, looking for ideas ?

Thanks ahead of time

Post your elevation, air temps, any intake, airbox, exhaust mods from stock. Take the float bowl off the carb, pull both jets and clean them and all passages in the carb. Same with the fuel screw and passage. Post what the jet sizes are. Check/set the float level to spec..

If you're feeling adventurous, take out the needle and see what clip position it's in.

Then we'll go from there.

Edited by Trailryder42

Thanks for the info, I will dig in and back to you, I do believe it is all stock setup but will get the details.  Do you know what the float should be set too?  Like base of bowl to float?  I know I need a shop manual !

Float level is 12.5mm measured from the bowl mating surface to the flat bottom side edge of the float, in line with the main jet, which makes it about in the center of the float.

There are links here for a downloadable shop manual. Use the search function.

Edited by Trailryder42

Thanks a lot, I can't wait to get this bike running good! Feels good to ride again, sold my cr250 23 years ago when I got married..

So just staring digging, see photo, if I'm measuring right I have about 6mm

image.jpg

So just staring digging, see photo, if I'm measuring right I have about 6mm, can't figure out how to get the needle out? Riding air temp is about 50 right now and I'm at 500ft above sea level.

image.jpg

Great video, to summarize the bike appears fully stock:

The jets are 40, 125, clip is in the third groove from the top, pin is labeled j75b. Carb float 5mm to 17mm.

Besides the lack of power it does seem like its lean

Thanks

Set float.

 

Those are stock jets but 125 seems very lean.  It's probably restricted with varnish.

 

Do you have any mods to exhaust or intake snorkel?

 

Assuming the air cleaner is not restrictied, try a 130 and richen the needle one notch. 

So lift the clip to the second from the top? No mods.

So lift the clip to the second from the top? No mods.

 

Negative on that.  

 

Lower the clip one notch thereby raising the needle to allow slightly more fuel in the mid range..

Carb float 5mm to 17mm.

Thanks

I assume that 17mm is the float being allowed to drop fully against its max drop stop. That is fine. Hold the carb as shown in the video for checking and setting the minimum drop spec of 12.5mm.

Ok I did all of the above, it's better but seems like it starves for fuel when reaching high rpms maybe I should go bigger on the main? Plug color isn't bad.

Trying to get a base line for engine temp, I have heat gun for checking and I'm at 165 top of the engine and warmer at the base area of the jug. And one more question is how much valve train noise is normal? Understanding that is hard to explain...

Thanks for your help

my 400 started doing the same thing couple months ago.... it was also smoking pretty bad previously and i had never done a top end so i went for it.... part of the new top end process was a new clutch which i thought would also have the same symptoms... one clutch plate was fried... easy to check...

Set float.

 

Those are stock jets but 125 seems very lean.  It's probably restricted with varnish.

 

Do you have any mods to exhaust or intake snorkel?

 

Assuming the air cleaner is not restrictied, try a 130 and richen the needle one notch. 

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