check the springs that hold the clutches in, one may be broken or weak,
SOLUTION: Remove rear pulley as a complete assembly then compress the pulley on the ground - hand pressure is ok. Remove old grease (brown because it was mixed with clutch dust) Clean, re-greased with mobile 1 synthetic grease (red) and reassembled and tested. Amazing difference. Clutch works flawlessly and there is NO MORE CLUTCH SQUEAK! Now acceleration is totally seamless meaning I can no longer feel the clutch "lock up". Also, I think starting will improve because the dragging clutch could have made the motor turn over more slowly (I will need to test for a week or so to confirm this theory).
Final Notes:
After testing for a week or so I will update. But if the smoothness holds I recommend that this clean and regrease procedure should ideally be done about every 8 to 10K miles. While I acquired the scooter at 2,600 mi and now have 19,500 mi and only did it because it was sticking to the point where it felt like it was stuck in gear - why wait that long. Remember the main clue is the squeaking clutch as you take off on a steep hill.
My Report:
I took the centrifugal clutch assembly apart and cleaned it. Basically, there are signs of wear on the sliding pins and I believe that was causing the sticking. I used mobile 1 synthetic grease and greased the bearings too. It operates much more smoothly.
Unfortunately, when I unscrewed part #[90202 90202-187-0010 NUT SPECIAL 28MM] the spring popped off and broke one of the giant [Outer Diameter] 45mm o-rings.
Note: the three springs looked fine, no signs of wear or damage.
The part that broke is: 91351-KHE7-9000 O-RING PINION CAP
I measured the o-ring slot with a digital vernier caliper and it is: 47mm and the O-ring measured 1.62mm thick.
The thin nut that locks the spring / clutch assembly in place measures 39mm
The other rubber seal that could be replaced if you felt like it is:
91211-KHE7-9000 SEAL DRIVEN FACE
UPDATE: 04-18-2016 I ordered the part from Chaparral Motorsports (they can order OEM parts for Kymco even though there website doesn't say it but you must look up the exact part number and call the order. The cost was $5.88 and I ordered two o-rings to be safe. The shipping was a whopping $12!! The order was placed on 4/12/2016 and as of 4/18 it is still not here and there is no tracking number yet. The other rubber seals (2) cost a lot more they were like $15 each? Apparently, Kymco's warehouse is on the east coast.
Today I picked up my order from Grainger online (I selected a local store to avoid delivery charges) the cost was 5.53 + tax and $0 for shipping for a 10 pack!
https://www.grainger.com/product/GRAINGER-APPROVED-%20-41KW36?cm_mmc=EMT-_-OrderConfirmStandard-_-GuestOrderConfirm-_-sku&RIID=178453235&GID=&mid=OrderConfirmation&orderNumber=1259529388&rfe=ec6db91b6d02d6a03fd5e1be1567309a688ed79a2cdb5ef13cb359c6e447afbc&origin=prodItem # 41KW36 Mfr. Model # M38801.020.0470 UNSPSC # 31181506
Item O-Ring Material Buna N Metric
Actual Width 2.0mm
Actual Inside Dia. 47.0mm
Outside Dia. 49.0mm
The only thing I would change if I had to do it again is go a little smaller: Outter diameter of 45mm for the inner o-ring because while the fit was perfect for the outter slot where the o-ring broke the inner slot was smaller and the fit was too loose by 2 or 3mm. The sell an o-ring with a OD of 45mm:
O-Ring, Buna N, 2.0mm W, PK10
Item # 41KW33
Mfr. Model # M38801.020.0430
O-Ring, Buna N, Actual Width 2.0mm, Actual Inside Dia. 43.0mm,
Outside Dia. 45.0mm, Cross Section Shape Round
