Do we have restricted rear pully ??

[Chris0381]

Just got some time as my seasonal job is winding down to carefully re-read the threads. One thread 11 pages long talks about the rear pulley being restricted with a bead of weld preventing the pulleys from complete closure not allowing the belt to get all the way up on the rear pulley.

The thread ended with no confirmation of this so I thought I would ask if it is confirmed.

And if it is confirmed, at this date what replacement rear pulley system would be recommended so I can get one on in about a weeks time.

Then a few questions:

1) Do both 50cc 2 stokes and 4 stokes have the 139QMB engine?

2) Should I use the contra spring that comes with the clutch or repalce it with the purple Malossi I have on now that is working well with my 7gm Dr Pulley sliders?

Thanks.

[zombie]

It depends on where the bike came from. Kymcos do NOT restrict the driven pulleys. Some of the china bikes do. You have to open it up, and look at the slide in the pulley shaft. It will be obvious  You can simply dremel it out.

The 139, 140 are both the same as far as the cvt goes. All the parts swap out.

If you are under 200 lbs use the purple spring. If you are 200+ use a malossi red.

Hope this helps

[Chris0381]

Thanks Zombie. My engine number is KF10 so was wondering if its a 140 or 139 etc. If you google KF10 you get foreign websites.

I took mine apart to use the purple spring and do see the bead of weld. Someone said you can't dremel it off so I was considering a new clutch with a $60 - $120 budget.

Maybe I'll consider dremeling it then.

Thanks

[zombie]

QMB 140 is the 2 stroke version, and 139 is the 4 stroke.
Your KF10 is the original Kymco engine it is copied from.

If you get a new clutch get a Stage 6 MK II. It' the easiest clutch to tune made.
If you open a dealer account w/ either SPI or Racing Planet it will run around 70 bucks.
For another 40 you can get a matching ventilated bell.
It's one of the best value for the dollar sets I have bought.

[Chris0381]

Thanks Zombie

I'll look into that. My assumption is unless there is something peculiar that regulates RPM's etc, then both 4t and 2t can use the same clutch. With the ability to swap springs, I can't see any need for two different part numbers.

Would you know the difference between the KF10AA and KF10CA listed on the Racingplanets website ?

[zombie]

AFAIK, the AA engine is the older NON emissions engine, and the CA is the newer bike made to meet US emissions.

Even if 'm wrong... all the CVT parts are the same.

[Chris0381]

Thats really good info. As one who used to work at an autoparts store in the 80's those numbers meant a lot. Still remember the 76 Chevy Nova having 2 diff manifold setups one integral and just a slight omission on a specially ordered gasket can really delay a simple repair; then all other parts we interchangeable after that.

[zombie]

With the emissions/non emissions bikes, all the parts are interchangeable, but you have to either scrap the emissions rigging, or drill out the cylinder head, and pipe.

Just the head, and pipe are different but they do fit each other.