2002-2011 Yamaha Zuma
Welcome to our crash course on the '02-'11 Yamaha Zuma, also known as the bugeye! We're going to go over some common upgrades, packages, and more in this section!
First Upgrades :
There are a few first upgrades we recommend for the bugeye Zumas! The first being a variator kit, and NCY pulley. There are a few variator options for this bike, but I usually like to run the Top performances "GP Trophy" kit, or the Malossi Multivar. The original Zuma variator uses 15x12 roller weights, where the Malossi and Top Performances kits use 16x13 weights. The OEM rear pullies on these scooters are super restrictive, causing a serious mid range bog, due to a sharp angle in the secondary sheave. We recommend getting the NCY Secondary Sheave to alleviate this issue.
Next, we would recommend doing an exhaust, our favorite options for 50cc, with room to upgrade to 70cc would be the Yasuni R, or Stage6 MK2 Pro replica. With a performance exhaust, you will also want to drop ~1 gram on each of the roller weights (Most variators come with 7 gram weights) along with getting some upgraded clutch springs, and an upgraded contra spring. You will also need to go up on the main jet ~1-3 sizes (stock is an 80, for reference) We have individual jets available for the stock carburetor, or full jet kits.
Big Bore kits :
Alright, you got the NCY pulley, variator, and exhaust and are still looking for more power? A big bore is going to be the next upgrade to consider! Most kits for the zuma are right around 70cc, which is a 40% bump in displacement, along with more aggressive port timing, these kits can really wake your scooter up! Please note : The stock crankshaft on the 02-11 Zuma should be upgraded with anything more than a medium grade sport kit to avoid catastrophic engine failure.
I recommend watching this very useful video Brandon made comparing all of the different cylinder kits for your Zuma!
Carburetor upgrades :
These Zumas don't need huge carburetors, the stock carb is Ø12mm, for most 70cc setups we recommend a Ø17.5mm up to Ø21mm carburetor. To run an aftermarket carb setup, you will need to swap to a single pull cable. To do this you have a few options. The cheapest option would be to get the S23 Throttle cable, and install a throttle stop so the throttle doesn't roll forward, to do this I usually put a screw in the side of the throttle housing. The other option would be our double delete kit, which includes a quick throttle, and grips along with a compatible cable!
The dellorto 17.5mm carb is a great option if you want to keep your scooter quiet, or are doing a sleeper build. This will require a choke cable, and a single pull style throttle cable. This carb uses the same style jets as the stock carburetor, M6 Dellorto round jets.
For a larger jump in performance (with the sacrifice of a little bit of fuel economy, and noise) We recommend the Polini CP carburetor. Typically we recommend the 19mm or 21mm option, this carb will require a single pull cable, and pod filter. These use Polini specific pilot jets, and PWK style main jets.
Clutch upgrades :
Probably one of the most overlooked upgrades, that makes a huge difference is the clutch, the stock zuma clutch is weak, doesn't cool or grip well at all.
There are plenty of clutch options, but our favorite options are made by Malossi, Polini, and Stage6.
Malossi fly combo : This is likely the best budget / bang for your buck option in terms of performance / sport clutches, $110 gets you a nice clutch, and bell! These come with white springs, which works good on stock scooters, but depending on your cylinder and exhaust setup you may need to change springs. There are two different spring kits available, one for race setups, and one for sport setups.
Polini 4race clutch : This is my (Paul) personal favorite clutch. It's easy to adjust, and has great grip! It also includes two sets of springs!
Stage6 Torque control clutch : This is Brandon's favorite clutch, it includes soft and medium springs, and also works on honda scooters along with yamaha scooters. Features an anti twist backplate, easy adjustability, and extra weights for more aggressive grip. We usually recommend picking up the race springs with this clutch.
Malossi delta clutch : This is also a great clutch, featuring full adjustability (not quite as easy to adjust as the polini or stage6) It also has a backplate to prevent twisting with super stiff springs for racing setups. There are two spring kits for this clutch, one for sport setups, and one for racing setups.
Clutch Bell :
Depending on which clutch you get, an upgraded bell is required/recommended.
Our top picks are