Clutch lever is suddenly loose, won't disengage.

[Jayraye39]

While riding, my clutch lever just gave out. No tension on lever or cable.

Also the clutch arm pulled in all the way to the bottom of carb bowl.

I disassembled the clutch system only to find everything normal.

The spring is fine, pin is fine, ball bearing is fine, bucking bar is fine. The only thing i see is a big divot on the push rod where the ball bearing seats. The bucking bar has a mild one also.

Could these divots be the reason the clutch wont disengage. Are both the bucking bar and push rods supposed to be flat at the ends

 

[Wrench]

While riding, my clutch lever just gave out. No tension on lever or cable.

Also the clutch arm pulled in all the way to the bottom of carb bowl.

I disassembled the clutch system only to find everything normal.

The spring is fine, pin is fine, ball bearing is fine, bucking bar is fine. The only thing i see is a big divot on the push rod where the ball bearing seats. The bucking bar has a mild one also.

Could these divots be the reason the clutch wont dis engage. Are both the bucking bar and push rods supposed to be flat at the ends

Did the cable break inside the housing where ya can't see it

 

[Chainlube]

The cable probably slipped on the arm, especially if you used the screw provided.

 

[Jayraye39]

No the cable wasnt broke and it never slipped on the arm. Although that is exactly what it did feel like. Took entire clutch assymbly out and inspected it. I ended up filling in the divots on the end of the pushrod and bucking bar with weld and filling it flat. Also filled in the wear on the end of the clutch arm where it makes contact with the bucking bar and filed that back to shape aswell. Reassymbled everything and greased. Clutch works better than it ever has. Thoes divots made by the ball bearing apparently can get so deep that the entire pushrod system will be so recessed in the housing that clutch arm will just rotate around the bucking bar. Crazy. 5years into the hobby and you still can learn something.

 

[ImpulseRocket]

A couple of fixes/preventative measures that can help extend the bucking bar life, and hopefully the ball bearing and pushrod.

A common one from the guys that run modified heavy duty clutch setups is to make a bucking bar out of a drill bit shank or a high strength bolt (Metric 12.9 or higher) of the appropriate diameter (5/16" or 8mm). The hardened steel deforms less under load and resists wear a bit better.

Something I have had great luck with is to use a a high moly content grease like Honda Molly 77 or Microlubrol M-77. on the end of the bars and on the ball bearing. These are high pressure lubricants used on spline and joint shafts to reduce wear - such as on the driveshafts for Honda motorcycles. The downside is, they aren't the cheapest things ever ($20 an ounce) but this is because they contain extremely high levels of molybdenum compounds, much higher than most standard moly greases.

I have M77 on hand by default due to the bikes I own, so it wasn't much of a stretch to use some. The Honda paste is sold in little 1 ounce tubes though, which is kind of nice not having to shell out a ton of money for a limited use item.

I only apply it to the contact surfaces, and utilize a standard high temp grease everywhere else, and it has done a brilliant job of reducing wear on the bars and the ball bearing.

I am also looking at buying a small quantity of high grade chrome steel high grade ball bearing balls to replace the one that comes with these motors. May not be necessary, but they aren't really all that expensive either. 100 of them from BC Precision is 10 bucks lol. At least I would have spares.

 

[Wrench]

A common one from the guys that run modified heavy duty clutch setups is to make a bucking bar out of a drill bit shank or a high strength bolt (Metric 12.9 or higher) of the appropriate diameter (5/16" or 8mm). The hardened steel deforms less under load and resists wear a bit better.

At least once a year someone claims they thought of that first.

 

[ImpulseRocket]

At least once a year someone claims they thought of that first.

Oh, I've seen it for myself when doing some digging around. The same stuff happens in the community for the Hawk 250 that I own. About every 3-6 months somebody comes along that "discovers" one of the many mods/fixes that somebody else documented years ago.