variator fan melting and coming off

[dutchman1965]

Bike had been running lovely for 9 months then belt snapped. Not a problem I thought. Replaced belt and snapped again after 8km but noticed variator cover/fan had broken off too ( thought wrongly that belt had fetched fan off) replaced both and same thing happened. To cut a long story short I've now through trials realised its the fan that's getting so hot it melts then slips then breaks away which then makes belt overheat and break. I've gone through 6 belts and 3 fans and a new variator set. Any ideas greatly appreciated. Its like kymco agility with a 139qmb engine so its the plastic fan type.

[wkreps]

Just tossing this out there but it seems that either it could be a bearing issue that is getting things hotter than normal in there or CVT covers usually have air flow going through one way or another. These aren't clogged are they? You using OEM parts?

[Chris0381]

Are you tightening that variator bolt correctly ? Are you pulling open the rear pulley assy. to slacken the belt so as not to pinch it between the variator pulleys when tightening also making sure the splines are mated properly?

[BettinANDlosing]

OEM belt or aftermarket? Something is wrong....... Have you made sure the fan is in the correct spot? The three little prongs need to be holding it perfectly. OEM new variator? Could be a lot of things.....

[dutchman1965]

Hi thanks for replies, I am wondering if it could be the crankshaft bearing creating too much heat though the engine sounds and runs great. I changed oil a few weeks back and after sieving found a couple of foreign bodies, though I presumed it was maybe remnants from rebuild work done previously. All vents are clear I've even drilled another one same size as original and put gauze over it to create more flow. Clutch has been taken off and stripped, cleaned and replaced feels good. The heat definitely comes from the variator end hence the change of variator. OEM belts have been used? With arrows travelling in correct direction. Hope this narrows it down.

[Chris0381]

If your bike is only nine months old, have you talked to a dealer. It should be under warranty.

[dutchman1965]

New crankshaft and seals, piston, rings, valves, gaskets etc.

[dutchman1965]

Bike is 2008, but only done 2000km gave it to son in june. He used it until November putting 6000 more on clock until he ran it dry. Lovely. Then after Christmas having done all the jobs above he had it back and ran it until mid April and then this happened. As stated it sounds great, it starts great but there sure is a lot of heat coming from somewhere.

[Chris0381]

I guess then that the shaft holding the variator is overheating from friction from someplace. Maybe bad bearing or looses shaft from aftermarket bearing that aren't very good quality and bad tolerances.

I replaced wheel cylinders in my 1997 Saturn only to have them fail in 6 months due to cheap chinese aftermarket parts when the original cylinders lasted 15 years; and the same for a water pump (1 year failure). Thats why I dread having to replace crucial parts on quality vehicles as there are some horrible aftermarket parts. Federal, Mooge and Bendix were my goto parts back in the days.

Since you have done all that work, my assumption is you know how to properly tighten a variator nut. So, I guess its the shaft heating up. I dont suggest its the rear pulley otherwise the heat would have to xfer thru the belt to the variator fan.

[dutchman1965]

I am hoping I know how to put variator cover back on but I can take advice. I know its splined and I'm using an impact drill to put it on with, other than that not sure what I could be getting wrong? Belt is getting exceptionally hot so heat transference is a possibility. But clutch isn't getting as hot. Just had a thought if I check the other end of crankshaft where it goes into other fan and feel how hot that end is, it may help narrow problem down, though I'm expecting it to be very hot anyway so might not help?

[Chris0381]

First off, is your variator and fan coming loose as thats one result of not tightening it properly (making sure the belt has slack when tightening the variator nut).

Im sure you put a washer between the variator nut and the fan as is stock with mine.

I guess if that belt deforms or goes jagged because of a fault with the rear pulley, there could be a point in time excessive friction builds up in the variator melting the variator fan. Also an higher tensioned belt from a high RPM torque spring could add extra heat.

I have to agree now it could be the rear pulley system as also a possible fault.

I would also ask if the plastic variator guides are in good condition and is the variator face sliding smoothly and evenly. Are the weights in good condition so the sliding movement is well balanced if bad weights could throw it off a bit.

The variator must get hot naturally, are you using a good quality variator fan or a cheap knock off thats not up to Kymco standards?

Binding brakes may introduce a lot of heat into the CVT.

There is quite a bit to look at.

When I changed out my sliders Saturday, the CVT was a bit clunky on initial start up. I think Ill open up my case today and do an inspection.

[dutchman1965]

Something was just written and can someone confirm either way. Should there be a spacer washer between the metal, splined and toothed variator wheel, and the plastic variator cover/fan this creating a gap between or should the plastic tlich the metal?

[Chris0381]

Well what bike do you have ?

Look at page 10 here as the Super 8 is like the Agility in a way also with differences here and there.

http://www.kymcospareparts.com/images/stories/PDF/Super8-2T-KF10AA.pdf

What exact bike do you have ?

[dutchman1965]

Thanks for the exploded diagram but the fan in diagram is a metal one (would be brilliant if they were interchangeable?).
Taizhou keitang. Apparently exactly as the yiben YB50QT-9A Which I believe is similar to the agility50

[Chris0381]

You may want to try a generic chinese scooter forum http://chinesescoots.forumwise.com/forum.html.

You could also try http://scootdawg.proboards.com/.

You could also be having some quality issues other than assembly issues.

I dont know that brand exactly but scootdawg search says its generic chinese but if it is a generic chinese scooter, I wouldn't put a lot into it. I hope it is a good scooter worth troubleshooting.

I hope you do get it fixed though at a reasonable cost and effort.

Good luck Dutchman.