Noticed a lot of people asking the same questions in various places along the lines of "how do I max this bike?" and "what's the best X I can get for it?" ETC. So Here's what I've learned over the time of maxing out mine for each part. Am not good at introductions, so I'ma just start.
EXHAUSTS
The People 50 2t only really has 3 options for pipes you can readily buy. The
LeoVinceTT,
stock and stock variants, and the
Arrow Extreme. Well, more if you count Tecnigas's options, but everyone seems to give them bad reviews and ignore them as a whole.
The stock gives you a good lower RPM take-off, and can be used with all stock settings- derestricted or otherwise. It limits higher RPMs though, and doesn't have that great of a top given the lower RPM power band. The heavy 9 gram stock weights are perfect for it, and keep the bike in that power band. The 9 gram weights do mean that you can't set it to 2 stroke at idle, and it will 4 stroke at all usable idle settings.
The LeoVinceTT is the best option for top speed. It's the largest pipe for the People50, and likes to hang around 8500 RPM for power on 70cc bores, and right below the stock cranks stable line for RPM on 50cc bores. It will however, kill your low end.
On stock 9gram weights, it won't be able to go over 30mph without going downhill to get the revs up into its use range. It's designed to be used with 5.5 gram weights on the stock bore. Which LeoVince thankfully supplies in the box with it. There are also 7.5 gram weights in the box for 70cc bores. Since it is a expansion pipe, changing the carbs main jet from a 75 (most years) to a 82 is recommended. The pipe is, however, restricted by stock for road use in europe, and requires you take a file/dremel/ETC to a single weld point to remove it for full use.
The Arrow Extreme is the smaller option of the two true expansion pipes. No special weight tuning is
required with it like the LeoVinceTT to be usable, but is still recommended for the best performance. The smaller expansion area lets it keep the stock weights, while adding a bit more power over the stock pipe. Is a solid bolt-on-only pipe not
requireing any adjustments, but still benefiting from them if you want to put in the effort. I wouldn't use a bore kit with it unless you plan on pairing it with excessively heavy weights to keep the RPM low and the bore in the pipes usable range.
TIRES
The stock tires are quality and don't need to be replaced/changed to get good traction, but-
If you'd like to increase the top speed. Changing the rear tire from the stock
100/80-16, to a 120/80-16, will net you
+5% to your top speed. Which isn't much, but can be the difference between the bike screaming and shaking like crazy to try and maintain 50, and it buzzing along happily at 50. The recommended tires in this size are
Pirelli Angel tires, or
Michelin City Grip depending on which you can get easier/cheaper in your country. Note, a 120/80-16 is the largest tire you can fit on the rear. I'd recomened keeping the front at the stock size tire, but changing it to the same model of tire. This will keep you from having to adjust the speedo, that takes readings from the front axle.
Cylinders Bores
Your two fully kitted options come from Mallosi and Polini. Mallosi's comes with carbon fiber reeds, and Polini's has the easier to grip piston pin clips. Both cost about the same now (though Polini's was usually sold for a bit more). Most people opt for the Mallosi kit. There are other "cheaper" cylinders, but that's in quotation as they either have no head, or occasionally not even a piston. Buying the separate parts, brings them up to the same price as full kits usually, so, defeats the purpose. There isn't much in the way of benchmarks for either, but most people choose Mallosi's. The power guesstimate for both is 8 to 10 HP, as no one has done dyno runs on Kymcos 2 stroke bores it seems.
Derestricting the airbox
The airbox has a small snorkel that limits the air intake (even on the smallest stock carb). Removing that tube (open the air box and just yank it back and forth till it comes free), and widening the opening for it out to full size,
will increase the air intake. Since you increased the air intake , you'll need a
much larger jet. The smallest it will work with on stock, is a combination of unplgging the "choke" (isn't a actual choke, but is a enricher) so it's always on, and a size 82 jet (average. area/altitude/temp/ETC effecting). The stock carb needle is non adjustable. I've been trying a few sizes to see what works best without disabling the enricher shutoff, but the size will range from anywhere between 90, to 120, depending on your location.
The end result is higher "free" power, but at higher fuel consumption.
This is arguably better then any of the aftermarket "performance" filters. As those filters have a extremely small filter area to pull air through. Where as the stock has a nice large flat filter that can pull air in with less restriction. A cone filter is the worst thing you can put on in terms of airflow. A open air foam filter won't restrict much, but will easily become covered in debri that would otherwise never have been sucked into the stock box. I'd recommend replacing the stock filter in the box, with a highly breathable one. Buy a square of the foam (it's cheap, like gasket paper) and cut yourself out a piece for the box.
This should give the same effect as using a larger carb on the stock airbox (in that you increased airflow),
but for next to nothing (maybe 10$, if that, for a jet+piece of foam). Seriously though, stock air boxes are extremely under-estimated.
Variator/GearReduction
Assuming you've already derestricted the variator,changed out the weights to match your parts and rider weight, and set the torque spring and clutch springs to where you want them-
there's not much you can do. You can't fit in a oversized variator without removing the starter and grinding a bit out of the case support braces. Meaning you're kinda stuck there. If you wanted to remove the teeth off the variator for the starter- that'd reduce rotational mass and technically let you have more power, but lets be honest in that removing that or the auto mixer doesn't do anything noticeable, and is only for racing eeking out everything last drop. Same goes for investing in a pricey aftermarket variator of the same size. As Kymco's stock one is already of high enough quality to not cause any real issues, making any improvments to weight or cooling not all that usefull.
The final gear ratio is stuck at stock. Jasil allegedly makes a kit with the part number of RP204004 ,but I've never heard of anyone trying it. Supposedly it "raises top speed +18%", but tooth/ratio numbers are not given from Jasil. If anyone wants to buy it, and try it out- leme know how that goes. I'm talking to a friend to see if they can help me make a CAD file for a set to give to a machine shop to make, but that'll be a ways off, and will likely be cost prohibitive.
The Sad Truth
We can get tons of power out of this bike. The issue is that no matter how much power we throw at it- we're stuck hitting a top gear ceiling that limits it to around 55 max. Unless you're into making a 0 to 50 rocket, it's a bit of an issue when it has enough power to be hitting between 60 to 70mph.
If anyone has input to add, let me know. Especially for the final drive issue. The large rims and low profile tires, let most tires for it get a S raiting. I want to do 65 right lane highway with mine. Which would make it fully usable as a motorcycle. Instead of being limited to 55mph and below roads.