Working on a '69 AT1B, and I am considering having the engine side cases powder coated. My guy believes he can get a very close match to the correct silver. I am currently stymied by the clutch release lever on the left engine case cover. The worm screw and lever appear to be pressed together perhaps (??). They are indeed separate parts in the parts manual, and I can just make out that the end of the worm screw looks to be a square or rectangle shape, so the little lever must be suitably shaped to fit over that?
I can only imagine that very few guys bother to do this during a rebuild. Just clean and grease and go with how it came in. I found nothing using the 'search' bar.

At this point it is more curiosity than need. I could be happy with how the cases are, just considering powder coating them and not sure these parts would survive the baking part of the process. 

I had done a post back in 2019 about that plastic worm screw on a 1971 JT1 mini enduro. It was cracked and I had to replace it. I came up with a homemade tool to press the new plastic worm screw together with the mating steel piece. It worked great. But that post is long gone along with many others.

They run straight in the case on the early ones & if you need to remove it the only way is drill the riveted over bit off then buy a new worn & seal, maybe arm too if looks compromised.
Then you need to start the worm/spiral on the right start point or arm ends up wrong when riveted on.
On a practice shot the arm should be against the seal & case pretty much, when its fully down.
Can remember now if its a two start or three on the spiral but you get that many shots at getting it wrong--or right. Not as difficult as i'm making it sound sorry. Grease it too on assembly.

I had an extra cover that was destroyed by a chain, so I checked this out.

To remove:
* you can not reverse it out due to the casing.
* there is no outer housing in the case to press out.

Dremel off top of pressed (its not really pressed but slides on) then sealed by what appears compression of the worm gear shaft. The lever arm will then slide off allowing removal off worm gear.

To install:
Note when facing L side of engine, worm gear is flush to outside of case area when lever at 3 o'clock position.  Test it before an after installing!

1. slide lever arm on. Add bolt or screw w/small washer. The adjustment screw on the outside for the clutch doesn't appear to seat all the way down, so you could put a short bolt on inside w/locktite as the threads are accessible. I tested this.  Now that I think about it, the screw may go all the way through. might not work.  check it out.  ha, it was an idea.

or

2. slide lever arm on. Tack weld it.

dremel off to allow remove of lever or maybe high heat would allow you to pull it:


clean up worm gear top, add screw w/washer + locktite or tack weld back on. Yamaha made it permanent, but I don't think you need much more than 3 or 4 tacked areas.

To be honest, you could probably just tape it off outside w/hi temp tape and powder coat it. 400F for 10 mins. I think that rubber gasket could probably take that.

Schu- is this the post you're referring to?  yamaha-enduros.com/index.php/forums/mini...disassemble-from-arm

Like the smaller twins, it looks like the arm/lever is fitted then "peened" at the factory.

CMSNL have one new one in stock!

CRANKCASE COVER ASSEMBLY (L.H.) ISO for Yamaha - order at CMSNL

Wow that's cool to think you can still buy a cover complete 56 'or so' years after they were first made.

I've just noticed it's a -01 version, so maybe the finish is different?