[Zappa]

Last Summer I came across a deal on a 2002 Zuma, which I bought from the original owner for $400, with 4200 miles on it. He's an older guy who lives at a campground from May - September and hadn't ridden it much since he bought a golf cart, so it pretty much sat unused for a few years. A buddy of mine heard it was for sale, so he passed the tip onto me. I stopped by to check it out, although it had no battery, it fired-up pretty quick with the kick starter, so I took it for a test ride. It sounded good and ran good, so I made the deal and loaded it onto my trailer. And that's how I became a Zuma owner.
I put in a battery and rode it around the lakes region on the weekends for the rest of the Summer. In the Fall I replaced the dryrotted OEM (2001 date coded) tires with a set of Michelin Reggaes, added a side kickstand and did the headlight wiring mod. Since the riding season is rather short up here, the Zuma has been mostly sitting in the shed for the last six months. But now that it's getting warmer again, I took it for a blast around the neighborhood a few weeks ago to blow the cobwebs out of it.
It does about 37-38 mph flat out, which isn't too shabby for 50cc, but most of the roads around where I live are posted 40-50 mph, so it's a bit dangerous if I want to go somewhere beyond my neighborhood and can't keep up with traffic.
I did some research and found a lot of performance parts available for these. I finally decided on a complete NCY 72cc kit with exhaust, clutch, variator and jets, from ZumasRus. Although the kit didn't come with any instructions, I watched some YouTube videos to help me get an understanding of what was to be expected. I have a background in mechanics, but haven't worked on a two-stroke since I rebuilt my old Kawasaki 125 dirt bike engine back in the 80's.
Anyway, I got it all done last Sunday, did the cylinder and exhaust swap first, cleaned the carb and installed a #95 main jet. The OEM jet was a #80. One of the videos I watched suggested using #95 as a starting point, so that's what I did. It fired right up, which was reassuring, then I took it for a blast. (without the air cleaner) I could feel the extra power immediately off the line, it bogged a bit in the mid range, but took off again when the revs came up. Pretty soon I had buried the speedometer, so I knew I had gained at least another 5-7 mph in top speed.
Feeling pretty good about it, I proceeded to do the transmission part of the conversion. When I got that done, and had everything all back together (with the OEM air filter installed) I took it for another test ride. Big disappointment. I couldn't get it to rev up high and the top speed was just under 30. Anyway, I ran out of time and daylight, so I put it away until I can mess with it again. I'm going to try running it without the air filter because it seemed like the engine was starving for air. I ordered an aftermarket K&M style filter, which should be here by next weekend.
Anyway, I'll search around in here for the right area to ask my questions about carb tuning and such.