Tach Gear Ass'y

[maximusrising]

Hi
1983 Heritage Special
I tried to reopen an old thread but it seems to not have worked. My tach cable disengaged. I was able to pull the gear/shaft right on out. So I had all the oil out anyway so I pulled the cover off because now I need to find the washer. Found that. Now, what does the 10mm head bolt on the outside do? Mine spins, goes in a ways comes out a ways but never gets tight. It also doesn't hold anything in there. I get how all the spinning happens, but how my cable just disengaged and how it's all supposed to stay together I'm struggling with

We'll talk about my slipping clutch in another post after I fill her up with Yamalube and see if the right oil solves that deal.

Thank you

 

[5twins]

That 10mm bolt should screw in tight. Sounds like the hole in your case is stripped. Also, the bolt is special. It has the tip turned down into a pin. This pin should fit into a little hole in the sleeve and hold it into the case .....

 

[maximusrising]

That 10mm bolt should screw in tight. Sounds like the hole in your case is stripped. Also, the bolt is special. It has the tip turned down into a pin. This pin should fit into a little hole in the sleeve and hold it into the case .....

Thank you. That explains a lot. Helicoil time I guess. Must have gotten cranked down a time or two with the pin not in the hole.
I'll have to figure out the thread to get the right drill & tap & helicoil.
Thanks again.

 

[5twins]

It's just a standard M6 x 1.

 

[maximusrising]

It's just a standard M6 x 1.

I greatly appreciate the help.

 

[maximusrising]

I greatly appreciate the help.

This explains a lot. That screw ain't going in that hole. Case thread is totally messed up. Suggestions on where to shop for something as random as that screw? Do you also find it odd that it's a specialty screw but almost completely opposite wrong? A flared flat end verses a smooth small diameter pin end? If it was a regular old bolt I'd feel a lot more like I knew what happened. Probably some jackass just plugging the hole?

 

[5twins]

It's not supposed to be flared like that, someone missed the hole in the sleeve and kept tightening. That explains both the flared end and the stripped hole. I don't think that screw is available anymore from Yamaha so a good used one may be your only option. An eBay search turned up a couple N.O.S. ones but they ain't cheap, lol. Take a file to yours and "fix" it.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=90109-06076-00+bolt&_sacat=0

 

[maximusrising]

All set. Thanks again It might be lacking a mm or so of engagement but it holds it in there.