NOT KNOCKING JD JET KITS! I have used them on many bikes, but---if a person is contemplating a new carb to replace a "less than ideal" or hard to jet carb, for 200 bucks more than a jetting kit or about the same price as a Keihin you could just buy a Lectron and be done with jetting for ever. I mean with all of this hype going on and masses of folks swapping over to these metering carbs, I see why places like JD may start to make kits for Mikuni's and other carbs for the guys who can't afford the 300 bucks. So that is a good thing. Just seems like a no brainer if you can afford it. Screw new pipes, carb mods and jet kits. Spend 300 bucks once and be done with Jetting and hello to better power, better fuel economy and better all around performance.
Well, I am finally healthy again, so I can finish this test! As a refresher, I was running the JD kit in a TMXX on my '12 300. Bike ran great, but starting, while improved, was still not as good as I wished for. I swapped the PWK on when I had some downtime the past month or so, and I've ridden it twice so far. Once for about 30 minutes on a short technical trail at my house (all first gear, easy to stall, super tight), and again for about 45 minutes at a local trail, which is some more open woods trail and some moderate hillclimbs. As far as low-end power, the PWK doesn't seem any different than the properly jetted TMX. I read about people saying that the PWK added a bunch of horses down low, and I just don't see that. It runs fine though, good throttle response, etc. I don't really know about top end power, nothing in either of these spots is open enough to really get saucy with it. I have a race in 2 weeks, we'll see how it does there. Starting is definitely easier with the PWK, which is really the main reason I made the swap. Cold it starts on the 3rd kick or so and idles clean, hot it starts in 1-2 kicks and will start with the throttle closed or slightly cracked. I can now consistently start the bike without having to lean it up against something, which is huge. Because of this alone, I am going to keep this carb for now. The PWK does have a bit of a "burble" at low revs and low load; I was riding out to my local riding spot and trying to keep quiet on the roads, so I was riding in 5th with real light throttle at like 35 mph, and it felt crappy. Not a realistic operating point, but still...
The difference between the pwk and mikuni is more noticeable on a 125 I've swapped back and forth many times. The pwk does have more down low . But I prefer the top end over rev feel of the mikuni . Makes more power IMO The mikuni does lug very we'll too though. I like the way the mikuni fits and cable fits better I also wanted to say that since putting on a cr ignition and adjuted the mikuni. I haven't felt any need to touch it . It runs perfectly . See how that goes when temp changes happen
It's been a while, but I just wanted to follow up on this for completeness. I ran both carbs (JD'd TMXX, PWK) back-to-back at one of the big national dual sports a couple weekends ago, so I was able to get a really good feel for the behavior of each. I believe that the PWK does have better "lugability" than the TMX, although it's a subtle difference. My riding style and terrain is such that I like being able to lug the motor and have some power available down low for singletrack obstacles, so I will be running the PWK for the foreseeable future. The JD'd TMX runs well and overall there's nothing wrong with the carb; if the PWK wasn't available, I would have zero problems with running it. However, in light of the options that are out there, I will pick the PWK. For a guy who likes the top-end feel of the TMX, the JD kit is probably worth the money!
