Hi all new to this Motor bike thing but loving it so far. I have a 66cc GT5 motor and have put just over 250 miles on it, in the city. Today less then a mile from home my clutch cable decided it was time to fray and snap. When I looked it appears the geometry here is very poor, it snapped right where it has to make a steep angle. Does anyone have a resolution to this problem or do I just replace my clutch cable every 200 miles to be safe?
Clutch arm angle, And cable snapping
- Thread starter onellesen
- Start date
Welcome to the forum.
There are several ways to eliminate the stress on the clutch cable at the point where it exits the cable guide at the engine.
One is to loosen the jam nut that holds the guide in the engine case and 'aim' the cable better toward the clutch actuator arm.
Another is a pully system that uses a wheel afixed to the engine that allows the cable to wrap around it instead of a straight pull.
I've experimented with a 'noodle' type cable guide that has worked well for me.
Also you need to make sure that you've eliminated all the friction in the cable. No sharp bends or kinks, lubricate the cable inside the sheath and assure that the cam and bucking bar as well as the ball bearing behind the bucking bar are well lubricated.
There is also a modification you might want to try. It involves sanding and polishing the bucking bar and clutch actuator cam contacting surfaces to reduce friction.
If you're using the small spring that comes in the kits that they tell you to install between the clutch arm and the cable guide, get ride of it. It serves no useful purpose and only increases clutch cable pull and puts more stress on the cable.
Hope these suggestions help.
Tom
There are several ways to eliminate the stress on the clutch cable at the point where it exits the cable guide at the engine.
One is to loosen the jam nut that holds the guide in the engine case and 'aim' the cable better toward the clutch actuator arm.
Another is a pully system that uses a wheel afixed to the engine that allows the cable to wrap around it instead of a straight pull.
I've experimented with a 'noodle' type cable guide that has worked well for me.
Also you need to make sure that you've eliminated all the friction in the cable. No sharp bends or kinks, lubricate the cable inside the sheath and assure that the cam and bucking bar as well as the ball bearing behind the bucking bar are well lubricated.
There is also a modification you might want to try. It involves sanding and polishing the bucking bar and clutch actuator cam contacting surfaces to reduce friction.
If you're using the small spring that comes in the kits that they tell you to install between the clutch arm and the cable guide, get ride of it. It serves no useful purpose and only increases clutch cable pull and puts more stress on the cable.
Hope these suggestions help.
Tom
One adjustment a lot of people miss is the flower nut.
Adjusting the flower nut can make a big difference in the angle of the clutch arm at the resting point. Most engines have quite a range where the clutch still works normally.
Try setting it up with the arm closer to the case when engaged. (loose)
Adjusting the flower nut can make a big difference in the angle of the clutch arm at the resting point. Most engines have quite a range where the clutch still works normally.
Try setting it up with the arm closer to the case when engaged. (loose)
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If you look closely at the end of the bucking bar where it contacts the cam in the actuator cover you'll probably notice the metal is rough. Some of them are badly pitted and that is actually a bearing surface. The cam is also prone to being poorly made and has a sharp, rough edge where it presses against the end of the bucking bar.
I use a Dremel with a sanding disc to smooth the end of the bar to take off the roughness. Don't remove a lot of material, just enough to give you a smooth surface. You'll also want to slightly round off the end so the edges are smooth and with a slight spherical look as opposed to a flat, blunt end.
The same for the edge of the cam. I round that off giving it a slight radius, or ramp to assist in the pushing action against the force of the internal clutch spring. After those parts are smoothed I use a bench buffer and buffing compound to further smooth the surfaces. When finished they look like chrome.
Use a good grade of bearing grease on the bar and cam as well as the ball bearing.
I think you'll be pleased with the results.
Good luck and let us know how you make out with the new cable.
Tom
I use a Dremel with a sanding disc to smooth the end of the bar to take off the roughness. Don't remove a lot of material, just enough to give you a smooth surface. You'll also want to slightly round off the end so the edges are smooth and with a slight spherical look as opposed to a flat, blunt end.
The same for the edge of the cam. I round that off giving it a slight radius, or ramp to assist in the pushing action against the force of the internal clutch spring. After those parts are smoothed I use a bench buffer and buffing compound to further smooth the surfaces. When finished they look like chrome.
Use a good grade of bearing grease on the bar and cam as well as the ball bearing.
I think you'll be pleased with the results.
Good luck and let us know how you make out with the new cable.
Tom
Maniac, What exactly do you mean, the lever arm has a nut on the top but it seems to be press fit in, are there splines on it so I can index it in some for a better "approach angle"?
I will be sure to let you know when I get it going, and I will try to get some pics up, she's not pretty but she is fun!!!
I will be sure to let you know when I get it going, and I will try to get some pics up, she's not pretty but she is fun!!!
