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Ty250 Clutch Lightener For 1990 Mono

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Does anyone know where I can lay my hands on a clutch lightener for the 1990 pinky I am rebuilding? I have seen and heard of the one that is basically an extended arm at the point where the cable dissapears into the gearbox. I am told the handlebar pulley type is not as good and also looks a bit bulky to me.

I have extended clutch arms on both the ty250 monos that have owned, on the first it was longer but straight, and on the second it had been bent round to maintain the distance between the end of the cable and the slot in the clutch arm. With a recently re-oiled cable they can be made as light as a modern bike.

I have seen this done two different ways.

-Cut and weld approx a 3/4 inch piece into the flat arm of the clutch actuator.

-A bolt on tab, die cast aluminum part that bolted onto the end of clutch arm. It extended the arm, and curved to move the pivot point very slightly (I think outboard). I don't know where to get one, the normal trials outlets in the US haven't seen them in many years. Should be easy to make if access to machine shop, or even a hacksaw and Dremel tool and carve it out by hand. I can measure one up if you need more info. Might take a few days.

In both cases, the critical part is the tiny clevis on the end of the bracket that accepts the ball of the cable. Clevis does not come with cable, it is riveted to the arm. When the extender is added, the rivet is ground off the original arm, and the clevis fitted to new bracket with a bolt. If the extender is robbed off (say from a salvage engine), then the original arm has no clevis to accept the cable. Bottom line, the clevis is not a separeate part from Yamaha, and hard to find. If anyone knows of source or acceptable interchangeable part, I'd like to know.

Also, thread the OD of the ferrule on the bottom of the clutch cable, and add a lock nut where it goes through the bracket at bottom of cylinder base bolt. Having the cable solidly bolted to bottom reduces the flex/slack motion and helps a lot.

With these two mods, you will have a smooth one or two finger clutch.

kcj

  • Author

Thanks for the replies, looks there is a niche in the market for someone to manufacture these!

If anyone has any pics I could use for reference that would be really handy

Cheers

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