01 Cr250 Pilot Jet

[mole1]

hi
i've got an 01 cr250 that i have rejetted to fmf specs ( 400main , 30pilot , stock needle 2nd clip , air screw 2 turns ) . it still feels rich off the bottom and burbles and seems to load up when trail riding in off to 1/4 throttle positions . the problem is a 30 pilot seems to be the smallest pilot i can find for the tmx carb , will standard vm28/486 pilot jets work ? i see the vm22/210 style listed in smaller sizes for tmx carbs but they dont look the same . i'm running 40:1 mix premium pump gas and the temps are in the 70's at sea level , is going below a 30 pilot harmful to my engine ? thanks

 

[motometal]

No, it's not harmfull as long as it isn't too lean. And if it's too lean, you should be able to tell by how it idles and runs.

Right now I use a 25 pilot, air screw about 1.5 turns out, with an S-7 needle jet with the stock needle, 2nd clip notch from the top, with a 410 main.

I have also run an S-4 needle jet with needle clip in the middle position. The setup with the S-7 is a bit smoother overall, I think.

The stock S-9 needle jet is just too fat.

 

[dirtybkr]

mole1,
the stock needle can't be used with the stock s-9 nozzle. You'll either need a s-7 nozzle($20) to be used with your stock h2-73 needle,or an h2-75 needle($10)to be used with the stock nozzle. The 30 pilot and 400 main,and a/s 1.5 turns out will work with either option.

 

[Glitch]

Someone sent a question into DirtRider mag asking about their 2002 CR250 loading up and fouling from closed to 3/8 throttle. Eric Crippa from American Honda said to run 400main, H272 needle in 2nd clip, stock slide, 32.5 pilot and air screw 1.5 turns out. Also to check the height of the float bowl and reeds, but definitaly float bowl.

 

[motometal]

the 2002 is a totally different engine with different jetting requirements.