Anyone looking to do this, go for it. But there's 2 ways and they both turn out to be about the same price if you buy a new PWK.
1. Get a PWK 38AS and all jets you think you'll need
or
2. By a Lectron and no jets needed.
But here's my story:
After waiting for warmer days to tune and only able to get to the bike shop on Saturdays, I got this puppy nailed.
Here's the skinny:
Bike- 03 KX125, Stock bottom end/cylinder, Wiseco piston, Phathead head w/ 9.3cc dome (stock is 10cc), FMF fatty pipe, PC 304 silencer.
Fuel: VP110/93 pump ~ 50/50
After researching some Husky forums that guys did PWK swaps on thier CR125's, I based the jetting off them for a start.
The new carb came with 55PJ, 170MJ in it as well as having the straight nipple on the top for any bike BUT a Kawi.
Fitment was pretty good but the PWK is a quite a bit longer from throat to throat, which made the air boot a snug fit past the shock. Good thing it's soft rubber.
As for the top, I searched and searched and you cannot buy that style top new anymore, as they are discontinued. Well, there's 2 answers for this. Thankfully, a member on TT sent me a Kawi top for free. Can't thank him enough. The other, which I found out after going to my local shop, the guy up there is a parts genius. There are parts and pieces made to adapt the PWK straight top to a Kawi style cable. I didn't know this until after the fact.
So, on to T&T. I first started with a 45 PJ & 162MJ. Pilot seems ok but AS wasn't making any changes and was cutting out at 2/3 throttle. So I went up on the MJ to 165 and left the 45. Low end was OK but had the dredded Bwooaaaag when cracking the throttle. So then I said screw
it and threw in the 55/170. Bad idea! I smoked the plug withing a minute or 2 having the pilot that big.
After returning from the bike shop on Sat. I now had another $40 in jets (I got a boat load of them, I wasn't playin!)
I left in the 170MJ and put in a 48PJ. NOW we're getting somewhere. It was running pretty good and very crisp, no bog and powerband hits hard. It was still just a little weak on the top, so I put in a 172MJ.
So now it's running pretty d**n good and I was able to start doing some real tuning with the AS and clip. After getting the AS set @ 1-3/4 out, it had some part throttle sputtering / crackling. So I began moving th clip around. Went up, got worse, went down and it cleaned up nicely at the 4th pos from top. No sputter, crackling and hits very hard and pulls for days. But the clutch was slipping on the topend so thats' being ordered this week along with a new inner hub that's needed.
So, I'm very happy witht he swap so far and my boy is liking it. Now to just get a clutch in it and get it on a track and really flog it. Biggest gain, easy jetting and 100x easier to do clip position changes having the "jelly jar" style top. And most of all, NO LEAKING FUEL!
BTW, when making changes and having to remove the top, those 2 pretty hoses going over the top will definately try your patience after the 2nd time getting in there.
Also, the only way to get the carb in and out easily is;
1. tilt back subframe and top shock bolt
2. R&R carb with intake boot on carb and slide in and turn. If the boot is bolted to motor and shock is in place, you're not getting that carb in there.
Here's the top I was referring to.
Calipers represent length of PWK
