Hi guys. Haven't worked on scooters for about 15 years now since the body isn't as flexible as it used to be, and I have forgotten most of what I knew then, so I guess it's best if I introduce myself as a noob and try really hard to describe my problem correctly. My daughter started getting a rattling noise from her Dink 50, so I asked a local mechanic if he could have a listen so I could decide whether it was worth my while investigating. He reckons it could be coming from the drive belt/variator area or, failing that, maybe the exhaust, although there's nothing obviously loose there. I pulled the cover off to have a look, but the belt itself looks fine. I decided to check the play and found that it seemed OK, but when I pressed it together in the middle I could almost make the two sides of the belt touch just with my middle and index fingers - and I ain't no Hercules. I ran the engine shortly just to do a double check with exactly the same result - tension OK at first, but easy to loosen the belt. Is it normal that the tension can be altered as easily, just by pressing the belt together, or does that point to a problem with the variator... maybe the rollers (weights?) What would be your best advice? Does enough evidence point towards the variator that it would be worthwhile either making or buying a tensioning tool to remove the bell, or would you tend to pull the exhaust off first and check it. Thanks in advance.
Good day sir. It is in fact completely normal to be able to pinch the belt belween the two pulleys. It becomes easier after the first time because pinching them together forces the contra spring to give a little bit inside the rear driven pulley and that allows the pulley halves to spread apart. Then the belt usually has enough traction to stick and not allow the pulley halves to completely close back together thus leaving the belt with a bit less tension. If it was a two stroke then id say you might be hearing the normal operation of the autolube pump. Basically you're forcing the rear pulley halves apart (part of the variation process) and the contra spring allows the movement. That doesn't mean that the contra spring isnt old, tired, weak and in need of a replacement though. However this should not be the cause of a rattle.
You may have heavily worn roller weights. Those can cause a rattle and a major decrease in overall performance. If a belt becomes overly streached (or wrong size) it can slap around on the upper and lower portions of the CVT case. You'll see evidence if this is the case.
Thanks very much for taking the time to reply, Kevin. I wasn't sure if I should be able to separate the two halves of the pulley so easily, but from your reply, it seems as though there isn't a problem there at the moment. The scoot is a two stroke, so there has always been a rattle, but it has gotten decidedly louder over the past week or two, so there is definitely something going on which needs to be hunted down. I have a feeling you may be right about the roller weights being worn, even though there hasn't been a noticable loss in power or performance yet. I remember working on a scoot years ago where I discovered only dust and crumbs where the weights should have been, and that was still running... it just took about 3 days to do 0 - 20 mph .
Well the vario and the rollers aren't worn, but they're all nice and clean and shiny now . I took the exhaust off, and when I shake it, there's something rattling around inside it. No idea what that could be, as I've never dismantled an exhaust before. I bought the scoot second hand, and don't have the original papers/manual, so I'm having trouble identifying exactly which part I need. The scoot is water cooled, but all I can find on racing planet under Dink 50 are for model numbers SH10CB and SH10CC, which I THINK are both AC... but I'm really not sure. Can anybody help me out here please?
Sorry man i just noticed your post. Have you tried looking under "Grand Dink 50"? Ive seen that model listed before but im not too familiar with that series of scoots. I looked around a bit but im still not totally sure. Id also assume that the bike would have a factory number plate in one or two places.
Forgot to update. A mechanic friend told me that the baffle(s) has/have come loose, which is what the rattling is, and it's not really a problem apart from the noise. Think I'll just let it rattle until my daughter decides she can't listen to it any more, since it's not all THAT loud
