Not sure how many folks still ride Kinetics (I am prepared for the hate...I think) but I figured I'd post anyways. I've seen a lot of posts on the forums regarding Kinetics and Spaco carbs and there seem to be experienced and extremely knowledgeable folks who know about them, hopefully you all can help.
I'm still new to mopeds, but I'm consulting Fred's guide, the forums and the wiki in order to become as self sufficient as possible with my bike. Basically, I bought a 2000 Kinetic Magnum (it is variated, as I believe all Magnums are) with 200 miles on it a few months back. I ran it at a little richer oil to gas ratio until I was over 300 miles on the odometer as the manual suggested this to break in the engine. It had a stock pipe until a week ago, and everything else about it is stock as well (or so I thought). Once I started running at the proper oil to gas ratio (50:1), I saw a little gain in acceleration and top speed, but I couldn't get over 22mph or so before the bike would start four stroking. At that point, I assumed I needed to downjet as everything I read indicated my mixture was running rich. As a precaution, I took off both my carb and air filter and cleaned both, but neither was dirty that I could tell. I took the bike out for a ride and I didn't notice any difference in performance. After the ride, I moved my air filter (original Piaggio air filter) just slightly with my hand as it looked a little crooked. I rode it again immediately and the bike was totally different. Better acceleration and it topped out at 27mph with no four stroking at WOT. I tuned in my idle screw and thought I was hot shit. Fast forward to a few days ago, I ordered a Vespa Piaggio techno circuit exhaust, as well as new jet screws from 50 - 60 (I assumed I was running somewhere around 45 - 48). I popped on the new exhaust and took apart my float bowl to upjet to accommodate the new pipe. Turns out I was running a 54 (not 45) screw the whole time, which is way bigger than I expected. I popped in a 57 (a little big I thought, but a good starting point) and road around for a while. Acceleration was a little lackluster, but the top end was sooo much faster. When I got back I attempted to better seat the air filter. After I did this, my acceleration was terrible and the bike struggled to get up to 20mph. I popped the 54 screw back in, seemingly no difference from the 57. I also attempted running without my air filter (no real change in performance) as well as running with the choke open (again no real change, after riding with it open for a bit I closed it and noticed a small gain in power but again no real difference).
To cut to the chase:
How does the air filter affect the actual performance of this bike? I read in the performance section that some bikes require an air filter for better engine performance, but I am unsure if this applies to my carb setup or if I should be running with the highest possible flow (which I attempted by removing the air box entirely)
How does the mixture screw on my carb affect jetting et cetera? I have seen others mention adjusting this screw but I am unsure of the best way to go about this. I assume opening the screw increases the gas mixture and closing it restricts flow, but again I am uncertain by how much or if to adjust this.
Also, due to the 54 jet I was running, I am unsure that my current carb is a 12.10. It seems it could be a 12.12 but I am unsure of how to determine this.
I apologize if I missed any details.
Sorry to write a goddamn novel about this problem, and apologies if I missed something obvious. Thanks a ton