Bicycle rolls freely when clutch lever is released

[bulldog87333]

Ok so first off I have read this thread (http://motorbicycling.com/showthread.php?t=22729) and tried everything on it. I'm sure the clutch cable is adjusted properly. I also tightened the flower nut completely so the clutch pads and plate were touching and it still rolls freely. I have had this bike for a year or so and it always ran fine. I let it set in the shop for a while, but I would ride it around the block once every month or so. The last time i road it, I left the gas valve on and it leaked for about a month. When I noticed it, I took it for my monthly ride and after taking my first turn it revved up like i pulled the clutch in. Now it just rolls freely. I checked the clutch pads for grease and it looks good with lots of pad left. I have a china girl 80cc. How can I tell if its a woodruff key or what the problem actually is? Any help will be appreciated and I will not abandon this thread, so don't worry about it being a waste of time. Thx in advance!

 

[Agreen]

Does it make any strange noises when it's rolling freely? How much difference in resistance between clutch engaged vs disengaged?

 

[Davezilla]

I've had something similar happen to mine once before and it was the screw holding the bevel gear down backed out enough for it to spit out the woodruff key... The bike worked perfectly on that ride but when I got closer to the shop I decided to go to the store down the street before putting the bike up, when I let the clutch back out it just free reved so it went from just fine to "I'm not going anywhere just by pulling the clutch in and releasing it again. You can check the bevel gear simply by removing the clutch cover, Sometimes the screw will cut a hole in the cover when it backs out, but not all the time, and all the screw needs is to back out about 5 or 6 turns to be able to spit out the woodruff key.

There are 3 woodruff keys in the drive train that'll leave it freewheeling like this, the bevel gear, the clutch hub, and the sprocket so its worth checking all 3 if the bevel gear is intact. It's also possible for a key to split or shear and everything will look ok at first glance so you may need to remove the gear or sprocket etc to see if the key inside is intact. One thing you can do if it did shear a key is use some red locktite in the keyway before you put the gear or sprocket back on (Do NOT get this stuff on the screw threads tho, you'll strip the head or snap the screw trying to get it back out), it'll prevent any small amounts of play and help prevent the key from breaking again, if a key is loose fitting to the point it can go in the slot or channel real easy and not stay put when inserted, you will need to fill that space somehow, the red locktite will work for a loose fit where the key and the channel are about the same size but the key can go in or out without any resistance, but if the slot or channel is slightly wider than the key a little jb weld will occupy that space and keep the key from being able to move around inside the slot or channel to help prevent it from shearing.
Some clutch pads like the black rubber ones can get damaged by oil or fuel saturation as it can soften up the rubber leaving them ineffective, this is pretty obvious so if your clutch pads were nice and dry when you checked them they're most likely not the culprit.

 

[crassius]

it is pretty easy to open both covers and just look to see where the turning stops

 

[bulldog87333]

Does it make any strange noises when it's rolling freely? How much difference in resistance between clutch engaged vs disengaged?

No, It sounds pretty normal while rolling. There is very little if any change in resistance when clutch is engaged or disengaged and certainly not enough to start the bike. Thx for the help!

 

[bulldog87333]

it is pretty easy to open both covers and just look to see where the turning stops

I only opened the the clutch pad side. I wasn't sure if I would cause anymore problem opening the clutch arm side. Can I just unscrew the covers and pop them off or do I need to do anything else first? Thx

 

[bulldog87333]

I've had something similar happen to mine once before and it was the screw holding the bevel gear down backed out enough for it to spit out the woodruff key... The bike worked perfectly on that ride but when I got closer to the shop I decided to go to the store down the street before putting the bike up, when I let the clutch back out it just free reved so it went from just fine to "I'm not going anywhere just by pulling the clutch in and releasing it again. You can check the bevel gear simply by removing the clutch cover, Sometimes the screw will cut a hole in the cover when it backs out, but not all the time, and all the screw needs is to back out about 5 or 6 turns to be able to spit out the woodruff key.

There are 3 woodruff keys in the drive train that'll leave it freewheeling like this, the bevel gear, the clutch hub, and the sprocket so its worth checking all 3 if the bevel gear is intact. It's also possible for a key to split or shear and everything will look ok at first glance so you may need to remove the gear or sprocket etc to see if the key inside is intact. One thing you can do if it did shear a key is use some red locktite in the keyway before you put the gear or sprocket back on (Do NOT get this stuff on the screw threads tho, you'll strip the head or snap the screw trying to get it back out), it'll prevent any small amounts of play and help prevent the key from breaking again, if a key is loose fitting to the point it can go in the slot or channel real easy and not stay put when inserted, you will need to fill that space somehow, the red locktite will work for a loose fit where the key and the channel are about the same size but the key can go in or out without any resistance, but if the slot or channel is slightly wider than the key a little jb weld will occupy that space and keep the key from being able to move around inside the slot or channel to help prevent it from shearing.
Some clutch pads like the black rubber ones can get damaged by oil or fuel saturation as it can soften up the rubber leaving them ineffective, this is pretty obvious so if your clutch pads were nice and dry when you checked them they're most likely not the culprit.

Thank you very much for all this info. The bevel gear by the clutch pad looked fine. i didn't notice any scratches on the cover. I don't have a gear puller at this time, but I can buy one if its a decent price. I was hoping I wouldn't have to do all that work lol. I will of course if its my only option. Thx

 

[crassius]

most of the time, the drive cover can be opened without even unhooking clutch cable - when open, do not lose the bucking bar & bearing that sticks out of the shaft - if the sprocket in there turns & the clutch doesn't, then you have a bad key on one end or the other of that shaft & you will need the kit puller

 

[Cylon]

Replace the clutch pads?

 

[Natasha]

I think I'm having a similar problem my will rolls freely with the clutch lever released and when I take the side off where the sprocket is where pin and bearing are it's still rolls freely cuz at first I tried adjusting the clutch and that didn't work and then I thought to myself let me see what happens when I take off the lever that pushes the pin in and yep it's still rolls freely so what do I do

 

[Greg58]

You have three keyways, one under the sprocket, one under each of the gears on the right side of the engine. Take off the right side cover and see what parts are turning as you walk the bike, if the clutch plate turns but not the gears the flower nut needs slight adjustment.

 

[Greg58]

 

[Greg58]

 

[xseler]

Yep, I've also experienced the woodruff key and shaft issue. Luckily it failed just a couple of blocks from home!

Best of luck in your repair.