ZX trans how-to

[evilone]

KYMCO ZX 50
what is a weld on stationary pulley???
this whole thread was started i believe using this exact clutch assembly.

it is a direct bolt on with case trimming.
not sure what it is your after.

That's the weld i'm talking about, above pic is the sym pulley weld that needed re-inforced.
Just curious if the Kymco weld is identical to the Sym weld or if it's a "beefier" weld that does not need re-inforced. Hope that makes sense.

[mookie]

with you now-
here it be-
looks pretty strong to me. what's the issue with the Kymco unit?
what sort of horsepower/ torque are you applying to it anyway?

[evilone]

Thanks Mookie, looks the same as the Sym. I don't think it really needs re-inforced but it was recommended by a Forum Hawaii member. I think they re-inforce them since most are strokers. I bet it's fine on a 72cc setup.

[dem0nk1d]

I don't know if we went over this. But you'll have to shim out the front kicker case with washers, so the kicker gear doesn't bind with the front pulley plate. "fly wheel"

[Wheelman-111]

Greetings:

The $20 Kymco ZX fixed Drive Face will require less (or no??) shimmage.

[evilone]

My cover is off a (I was told) SYM dd50. Works perfectly.

And it was posted in first part of write-up. You need to shim it about 1/8 inch. Thanks for looking out though . Have you done the swap? If so, what are results?

[evilone]

Greetings:

The $20 Kymco ZX fixed Drive Face will require less (or no??) shimmage.

Do you have the ZX drive boss wheelman? Or is the stock boss shimmed? Curious what measurement you have with boss and shim if that's what your using.

[dem0nk1d]

I got a engine that was shipped from the island which is already setup. The motor needs to be rebuilt, but i'll get measurements and try to get part numbers off the setup including the belt.

[808BMW]

My cover is off a (I was told) SYM dd50. Works perfectly.

And it was posted in first part of write-up. You need to shim it about 1/8 inch. Thanks for looking out though . Have you done the swap? If so, what are results?

I don't have any shims, it works perfectly with a paper gasket (extremely thin) and nothing else. I've used the very thick rubber SYM gasket with a honda kicker case, it still needed more spacing.
Out of all my personal friends, I'm the only person that doesn't have washers on the kicker cover.

I've been running the ZX setup for about 6 months, so I can't really compare to elite stuff very well. My first thoughts was that the elite setup has a much better top end, but different center/clutch springs in each pulley doesn't make for a very fair comparison. I eventually got a comparable top speed, with better low end, but it took a lot of tuning.

[Wheelman-111]

Greetings:

I have shaved the cases, priced the parts, but have not yet installed any Kymco ZX parts with the exception of the outer front pulley. The thinner kickstarter castle doesn't need any shims to clear my current shim - I'm using a slightly-shimmed (~1mm) stock SA50 drive boss and a 16.2mm wide Polini belt. The low end take-off is markedly better than all-stock, but I believe the bigger rear ZX pulley would be better still. I still haven't tested top speed with my adjusted shim thickness, but the stock belt ran 3-5 MPH faster than the wider Polini. I still haven't completely solved that riddle.

[mookie]

i bought NEW the ZX clutch assembly and a new 18 669 32 belt.
for sale never used mounted nothing

90 shipped.no i won't take or consider lowball offers, but hey-Thanks


Mookie

SOLDTHANKS!

[Wheelman-111]

This is from Flash IV begins - thought I'd add to this excellent thread for would-be ZX-converters.

I recently got a brand-new Kymco rear pulley. Speaking to Keoni at VT cycles about ZX conversions a while back, asking about ZX parts. He said they were out, can get 'em, but discouraged me to try. Something about broken belts. Took a closer look at Flash's belt case. There are a few places where you could see problems developing, mainly at low speeds/belt-in-low-gear, but one problem for High Gear as well. This is particularly true if the user plans to run the longer 669 belt:

See how it lives near the rim of that rear pulley? The prep I'd done appeared not to be sufficient. Worked some more.

Here's an area that could be a problem if the belt rides up to the rim of the variator:

One more spot to examine at the upper rear:

Not an issue under power, but under engine braking the belt can "slap around" on the low-tension side. I'm pretty sure this is the reason for reported belt breakage. The alignment looked pretty good using the stock SA boss shimmed out 2.25mm. The KymcoZX pulley was a whopping 4mm longer than the Honda AF16 item, and it put the belt out too far at the front.
Photos show grinding roughed in with a carbide rasp. I went back and polished the surfaces with a fine stone so that if there is incidental belt contact, it will be smooth.

I'm pretty confident this block won't be a belt-breaker, but I'm glad I didn't have to squat down beside the scooter to get this work done. It's also a good thing I didn't try to install the ZX pulley into Flash III, because I now realize the crankcase belt cavity prep I did squatting - at night - in the cold rain - wouldn't have been sufficient.

I'll also add that running a longer belt is required to obtain faster take-offs, because a stock-length belt will not have enough length to wrap around the rim of the ZX driven face. However the longer belt will be too long for the full variator stroke to pull it down far enough toward the center of the rear pulley for best top speed, unless the variator is also enlarged. I've got a BrandX-for-Ruckus variator that measures 97mm across the drive face that should do the trick. Polini for Ruckus is 94.66 mm and should also be enough to take up the extra slack.

[Wheelman-111]

Greetings:

The Kymco ZX belt cover is a no-go. Evidently Kymco's blocks are a good bit longer between the crank and clutch shafts. The block belt cavity itself sticks out farther, needing a much narrower cover which of course won't clear the Honda clutch shaft. The forward 3 bolt-center holes line up pretty well with the SA/16 block. However the Kymco cover has the hollows for the locating dowels cut into the wrong holes for use with Honda.

I thought about pulling out high-precisiion Wheelman Hacksaw and making short work of the back half of this cover, but on second thought I might want to see if I can return the cover for credit. Maybe I ordered the wrong "ZX" cover?

[dem0nk1d]

i think the sym dd50 cover fits the af16e

[808BMW]

Yup, go with the dd50.

As far as case clearance, I was scared to get close to the thread on the lower part at the rear. I mainly had to clearance the metal "rib" sticking up.