Ty175 clutch

[Dave anderson]

Hi all, would like to know if the clutch housing should have play in it? Eg, clockwise and anticlockwise, any help would be greatly appreciated. Regards dave.

[David Lahey]

The TY175 clutch basket has a set of rubber discs that sit between the big gear and the clutch basket and they act as a shock absorber. The fit of the rubber discs is what allows a bit of slack. I've never seen a standard one that didn't have free play in it and the free play does not cause any problems.
When I was a kid I thought I could improve the motor by reducing the amount of slack in that setup so I pulled mine apart and fitted custom made rubber discs that were a firmer fit. I could not feel any difference in the way the motor behaved while riding it after doing that, so it was probably a waste of time and so I have not bothered doing it to any other TY175s.

[Dave anderson]

Thank you David.
It's been a while since I worked on a Ty . Iam figuring that the fingers holding the clutch plates may need deburing,would you suggest a fine file? Thanks dave.

[David Lahey]

I used to file them, and they did work better afterwards but I was never happy because they might be uneven or not square, especially some that I had filed quite a few times.
For the most recent trials clutch I worked on, I had the finger edges machined flat and exactly evenly spaced using a milling machine. Didn't cost much and it works beautifully. The person who did mine has done lots of them.

[Dave anderson]

Would that make the friction plates fairly loose in the fingers,or does it not matter as they need to expand and contract?
And also David would you know the talk for the clutch nut thanks once again.

[David Lahey]

Yes it increases the gaps between the friction plate tangs and the fingers each time you machine or file the fingers. The width of the gaps does not seem to cause any problems that I have seen as far as clutch action goes. There has to be some clearance so they can freely slide along the fingers. Eventually after many cycles of wear and re-machining, or filing, the fingers will become too narrow to support the load whether you file or machine them. At the wear rate I've seen on my most-thrashed TY175 motor, I reckon it would take a few centuries to get to that point.
If you are a top level trials rider and are hotting the motor up and are going to use clutch-dumping techniques for launching up big obstacles, the clutch fingers will groove up faster than from normal trials and trail riding use

[David Lahey]

Yamaha TY175 service book says clutch nut 520 to 600 inch-pounds

[Dave anderson]

Wow that's a lot of tork. David when everything is back together should there be clutch action ? As with mine there's just cable action ie, no plate movement .
Thanks once again dave. You should give me your number so I can talk to you Lol.

[David Lahey]

There is normally a steel ball between the mushroom and the pushrod. The slack might be from the ball falling out unnoticed.

[Dave anderson]

Thanks very much David i will check , hopefully I will find the little sucker. And thanks again for all your experience.
Regards dave.