39 pwk needle

[shang]

Hey, I have a 39 pwk that I just put on my zilla. I am having problems with it running crazy fat in the mid, and lean on the top. It currently has a 1469D needle in it. What needle are you guys running in your pwk zilla's? This thing is in the leanest clip position and it is still fat. I know they are all different, but I need a starting point to get this thing jetted right.

Thanks,
Shane

[ProTTZilla]

It currently has a 1469D needle in it.

Are you sure that is the number on your needle???I'm gonna go to the shed and see how they are labeled.

[shang]

Yes, thats the only number on it. It might have a letter in front of it, but I don't remember and the bike is at a friends house at the moment. Apparently the KTM guys are familiar with the 1469D, but I didn't see it on sudco or keihin's site.

[ProTTZilla]

It maybe an after market needle or even may belong to after type or brand carb.Or a needle made by a bike manufactureer for when they use a Kiehn carb.Since your haveing trouble I would buy a dgh needle from sudco and see if that help thats what I'm running in mine Zilla.Thats a standard needle if you were to buy a new untouched carb from Keihn.As far as being lean on top wot is all in the main jet.So just fatten it up till it noses over at wot then drop back 1 size and then do a plug chop.

[shang]

Thanks, yeah I tried jetting up for wot but it wouldn't clean up enough in the mid to rev out. I will try the dgh and see if that gets me close. What needle position are you in?

[ProTTZilla]

I always start with postion 3 and make changes from there.But if memory serves,I'm pretty sure 3 was the magic no. for me.I will look at it tommarrow and see for sure.

[ProTTZilla]

Oh heres a real good page on jetting carbs if u need it.http://www.duncanracing.com/techfaq/...-jetting.phtml

[shang]

Thats probably one of the best tuning guides i've seen. Thanks! And thanks again for your help!

[flotek]

the circuits overlap it is not uncommon to have a crappy midrange if your pilot jet is
too large ,what main are you running ? i wouldnt be too quick to change out for different needles till your sure of what your engine wants .A 48dgh needle is stock for a 39pwk keihin carb

[shang]

I've been from a 185 down to a 165 and back again. I plug chop halfway up Thunder mountain at St. Ann's said the top was lean with a 168 and it wouldn't really clean up. Lugging the thing back to camp in the mid the whole way showed a very black and very wet plug. The needle is in the leanest position and the bigger I go on the main obviously the worse it gets in the mid. I couldn't really get a good read with a bigger main because it wouldn't clean up enough in the mid to reach wot. It had a 42 pilot in it when I bought the carb but the idle screw had to be run almost all the way in to get it to idle. I changed to a 48 but it didn't change the idle at all, but I have played with the air screw a little. It starts easy, but it always has started easy. The carb is off of an 06 KTM 125sx if that matters.

Thanks again for all the help!