38TM to 36PWK jetting, any ideas??

[steve.emma]

hi,
bike is a 90' yz250 and along with some other minor mods i am fitting a 36pwk keihin carb instead of the standard 38tm mikuni. the pwk is off a kawasaki 125 (90' i think). the jets that came in the pwk are 158 main and 48 pilot needle is a N0EJ. basically what im asking is does anyone know what a baseline jetting for this carb would be on a 250? i know jetting depends on a lot of variables but i just need an idea of a starting point. thanks in advance.

 

[bclapham]

you will have to do a little bit of detective work- just look for any 250 that run a 36mm kehin and use that to begin with.

 

[CharlieT]

On a 36 PWK, I'd go with about a 52-55 pilot and if stock motor, around a 175 to start with.

 

[steve.emma]

thanks guys, yeah if i can find another 250 running a 36pwk then that would be a good startting point, but im unsure what bikes this would include. what about kdx250's what carb do they run? (i did check the kdx forum but couldnt find this info).

 

[Detonator]

My 2004 KTM 250 EXC runs a 36 PWK. Here are the specs according to the manual:

Based on an elevation of sea-level to 1000 feet, 16 to 24 degrees celsius:
1) Air screw 1 turn out from full clockwise
2) 35 idle(slow) jet (I run 38-40 idle jets for my setup...works fine)
3) N3EH needle in the 3rd clip from the top
4) 162 main jet (I run the 160)

These are baseline only. You might not get full performance from these, but you likely won't grenade your bike. If your temp/elevation are different, let me know.

You can send me a delicious sheep as compensation.

 

[steve.emma]

hey thanks heaps Detonator, that was just the info i was after
im riding pretty much near sea level here so will try those jets and fine tune from there. i didnt realise any 250's ran a 36pwk carb, im only doing it to try and turn mine into more of a trail bike than a motocross bike.

as for the lamb, yes kiwi lamb is the best i will try and email you a virtual sheep!