Horrible Noises From Underneath

Nulldevice, the sound gets worse the longer the scoot runs. It also gets worse as you ride faster. I had it down to 10mph from 20mph because it was clunkin' and squeakin' around. It doesn't matter if brakes are used or not. The noise is underneath me and toward the back.

As far as the CVT, is that kinda like the primary cover on a Harley, you know, down on the left side of the bike, where I put the gear oil in? It's black?

I can definitely hear the chirping! around 1:50 secs and stops at 2 mins in I can make out a kind of even, cyclic sound that doesn't match the wheel rotation, it's playing out a beat like you might make tapping your foot to some fast music, like 1..2..3..4..5..6..7.. to me it sounds like a slower than rear wheel gear or shaft that's making that particular sound about every say, 5th or 6th wheel rotation.
I'm not familiar enough yet with the gear box to tell what might make that noise, but it could also be a bad bearing that has a binding condition that causes it to lock up and release during a certain part of it's rotation and a shaft it's on is slipping (causing the chirping or the other noise I hear) or the outer race of it is turn inside the case, which is less likely since being aluminum it would wear down pretty fast and the noise would change.

What I would do if this was my bike, is take off the CV cover and inspect, and then almost certainly take the BELT off so the rear wheel can spin free of the belt, and other parts and turn the wheel by hand and feel what's going on, if there is binding, difficulty turning it, grinding/crunching feeling, loose/wobble/play.
I would then take the wheel off and turn the shaft by hand (or try to) and see if I felt the same things- that eliminates the wheel and brake stuff from any possibility something is rubbing.

Next I guess the clutch needs to come off, be inspected, and eliminated as a source of grinding, problems, but I think you'll find the problem is going to be related to; wheel bearings, or gears.



That's because the parts are getting heated up and tighter without a doubt, so that again suggests to me bad worn bearings that could be missing a ball or they are worn out of round, and/or oil has not been getting in where it's needed which ruined the bearings.
Lube is almost certainly not getting in the bearings I'd say.

I had an 82 honda cvcc, when I took the transmission apart at 200,000 miles, the main shaft ball bearing was missing TWO balls, they were nowhere to be found, I have to assume they just got worn into powder. I read it's a common failure with that particular bearing which I was told was a "cheap" one.
There were no symptoms at all, but goes to show that ball bearings do break and can lose parts, sometimes you don't know it- they still run ok, other times they seize up when the balls try to roll over each other because their stamped holder is gone, and get jammed.
That happened to me twice in 2 years with a utility trailer at work- the wheel bearings just came apart.

All of this reminds me of the grief I had with my swing arm/spacer/bearings. Somehow the spacer rode against the snap ring clip, the clip cut a groove in the spacer which formed a rough edge like a tin can, it cut into the bearing seal, popped it out and left bearing grease all over the place, and get this, it had a little over TWO miles on the odometer! (guess I got lucky wanting to change out the Chinese tires for Pirellis!) I then used a brass drift pin to tap out the old bearings and replaced 'em with some very high quality Japanese Ceramic ones I won't have to be worrying about. This just goes to show you that (unfortunately) when dealing with Chinese bikes check EVERYTHING and take nothing for granted.

That is the cvt cover under the airbox. You shouldn't need to take kick starter off. There will be no gear oil in there. Do a quick YouTube search for scooter cvt and there should be a video about taking it off.

This youtube video is FANTASTIC, Lee! Is that why they pay you the big bucks? :-)

Hiya MP, yep the cvt cover is the elongated pill shaped cover (on the left side?) that houses the drive belt/clutch, the swingarm is on the other side (and no there shouldn't be any gear oil dripping out.) BTW, get small plastic bags for screws and small parts as you disassemble (I mark the location of them on a small slip of paper and put it in the bag so I don't forget what goes where.) As to the bearings, if you've already taken the swingarm off and are going to be working on it anyway I'd go ahead and replace the somewhat spotty Chinese bearings with better quality stuff (you can find the size of your particular bearing stamped on the seals.) I'll look up the website and post it (I think I should tell you I had a bit of a hard time on the phone with these people in getting my order filled.... But customer service is DEAD these days right?) the rear (ceramic bearings) weren't exactly cheap, if I remember right they were something like $60 bucks each, but I feel it was well worth it. I'm going to lookup the bearing supplier and post, if you order from them call first to see that what you want is in stock and if/when you receive an email order confirmation MAKE SURE the the order number is on it!!! Hope this helps! Spandi.

Thanks, Spandi! I'll check it out.

Get the best bearing you can afford (you won't regret it.)

Found this as well. (haven't bought from them yet.) www.bocabearings.com/bearing-applications/motorcycle-bearings

Also make sure about the RPM rating and motorcycle/scooter application and suitability ( the folks there should be able to answer all your inquires.)

Hi nulldevice, I'm certainly not too crazy about spending the $60.00 bucks either, but I'm worried if I get a cheapo set of bearings the same dang thing's gonna happen down the road. Epicboy stated in an earlier post China scoots were notorious for being inferior. A lot of stuff nowadays, like engines, are made of ceramics due to their heat resistance and their strength, so I figured ceramic ball bearings would be superior. Besides, you get what you pay for, right?

Hmmm, makes me wonder if I shouldn't address the front bearings before THEY start squawking...I know, I know, don't INVITE trouble...

You're not just saying this because the packaging is color coordinated are you? ...and BTW, don't you mean "forefront"?

Sorry \\-olf (is this Wolf?) but when I read "stands in the forehead" I just rolled.