Gentlemen; While I was putting a small dab of grease on the two drive gears of my Chinese 66cc engine, I noticed that the large one was a bit loose on whatever it is attached to! Is this normal or do I have a problem? Please advise.
Large Gear seems to be loose!
- Thread starter Bicycle Motor Fun
- Start date
bmf, the large gear is the clutch plate and should be held snug by the clutch spring when engaged. if it's wiggly, it's probably the main driveshaft bearings... if the clutch is NOT slipping horribly when trying to operate it.
There's bearings between that clutch plate with the gear, and the pucks in it, and the main driveshaft, but they would only show evidence of looseness when you dis-engaged the clutch by moving the lever.
Norm did a thread on clutches, and I did a few pics on how I took mine apart to grease those ball bearings. It's a little tricky, but do-able.
I did NOT pull my driveshaft because my bearings were good.
Biknut's recent teardown describes where you can takes off the chain sprocket, then drive the shaft out towards the clutch side of the engine... to replace those bearings.
Good luck
rc
There's bearings between that clutch plate with the gear, and the pucks in it, and the main driveshaft, but they would only show evidence of looseness when you dis-engaged the clutch by moving the lever.
Norm did a thread on clutches, and I did a few pics on how I took mine apart to grease those ball bearings. It's a little tricky, but do-able.
I did NOT pull my driveshaft because my bearings were good.
Biknut's recent teardown describes where you can takes off the chain sprocket, then drive the shaft out towards the clutch side of the engine... to replace those bearings.
Good luck
rc
Thanks Rustycase; the clutch does not slip at all and this looseness in the large gear, is when the clutch is engaged. Humm, maybe I will have to take that side apart to see what the heck is going on. I'll search here to see if I can find those photos of dis-assembly of the clutch area. Thanks and if you have any other thoughts on this, please pass them along to me as well.
lol
Yah... suspect anything I say and get other advice! lol
sometimes I'm a real hack on things.
Norm, Biknut, and others are far more particular AND experienced than I.
rc
Yah... suspect anything I say and get other advice! lol
sometimes I'm a real hack on things.
Norm, Biknut, and others are far more particular AND experienced than I.
rc
Rustycase; is this large gear attached somehow to the clutch pressure plate and it is coming loose? I have never had one of these engines apart and any of the Utube videos that I have found, don't give me this info. Like I said earlier, the clutch works perfectly. Thanks again.
bmf, the most wonderful thing abt china girl HT motors, besides being cheep, is they are ez to work on !
inside the drive coverplate first thing u see is that large gear, with the pressure plate of the clutch over it's center.
The gear IS the clutch disk... it is a carrier for the 15 'pencil eraser' clutch pads. it rides on "Norm's 52 ball bearings that go everywhere when taken apart" the race which is pressed onto the hub which in turn is bolted to the main drive shaft. the main drive shaft is hollow, with the bucking bar and ball bearing inside it that pushed out the pressure plate to dis-engage the clutch.
lol
probly FAR btr to search down Norm's thread on clutch stuff or look at my pics.
Glad to see you're having fun with china girls! lol
rc
inside the drive coverplate first thing u see is that large gear, with the pressure plate of the clutch over it's center.
The gear IS the clutch disk... it is a carrier for the 15 'pencil eraser' clutch pads. it rides on "Norm's 52 ball bearings that go everywhere when taken apart" the race which is pressed onto the hub which in turn is bolted to the main drive shaft. the main drive shaft is hollow, with the bucking bar and ball bearing inside it that pushed out the pressure plate to dis-engage the clutch.
lol
probly FAR btr to search down Norm's thread on clutch stuff or look at my pics.
Glad to see you're having fun with china girls! lol
rc
Start at # 37
Chinese HT breakdown pictures by Ron-Becker - Photobucket
Parts blow-up
http://www.zoombicycles.com/eShop/Parts-and-Accessories.html?TreeId=3
Chinese HT breakdown pictures by Ron-Becker - Photobucket
Parts blow-up
http://www.zoombicycles.com/eShop/Parts-and-Accessories.html?TreeId=3
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Thanks to you Al Fisherman for the great links, especially to Ron Beckers Photobucket! It doesn't appear to me that the large gear is a separate piece screwed to something else. My question is, coule it be coming 
loose from its mounting? When I get back to my bike, I'll pull that side cover and take a really close look. But, that will be in a week or so; I wish I had the bike here with me in the city. But riding it down those very little traveled country dirt roads, makes that mountain bike feel right at home! Thanks again Al.
loose from its mounting? When I get back to my bike, I'll pull that side cover and take a really close look. But, that will be in a week or so; I wish I had the bike here with me in the city. But riding it down those very little traveled country dirt roads, makes that mountain bike feel right at home! Thanks again Al.
For clarity, what are we referring to as clutch "engaged"? When the clutch is not gripping (handle pulled), the large gear is going to be a bit loose. It should be tight when the clutch is engaged to grip the plates (clutch handle let out).
I wouldn't worry about it.
I wouldn't worry about it.
Thanks Pilotgeek! 
This is my first experience with this little 66cc engine and I am having a ball "getting into it" so to speak. I have it on a Tuffy mountain bike that was given to me and I have it up at my son's farm here in Michigan. There, I can run the quiet dirt roads through the farm areas and enjoy the ride through the countryside. Pedaling this bike would not be the same! It does seem odd, however, to be riding along at a good clip and not having to pedal! Thanks again for your input. Regards, Karl
This is my first experience with this little 66cc engine and I am having a ball "getting into it" so to speak. I have it on a Tuffy mountain bike that was given to me and I have it up at my son's farm here in Michigan. There, I can run the quiet dirt roads through the farm areas and enjoy the ride through the countryside. Pedaling this bike would not be the same! It does seem odd, however, to be riding along at a good clip and not having to pedal! Thanks again for your input. Regards, Karl
Yeah, no problem. My secondary gear is loose like that when the clutch is not engaged, and it has been for the 1000 miles I've had it. Even took it all apart to see if it's anything abnormal, and it just seems to be the way they're made, if that eases your mind any more on the matter. Happy riding =)
