tacho drive bolt

[ace cafe racer]

decided to fix one of my many oil leaks starting with the tacho drive, came to undoing the bolt that fixes the drive in, lo and behold it just pulled out seems no thread left on housing. What size should this bolt be, thread, length etc so I can helicoil back to what it should be.

[Trigger]

That will be a JIS M5 but, not easy to helicoil . Measure the depth of the thread and see if there is any thread at the bottom. Someone may have put a screw in too short.

[ace cafe racer]

That will be a JIS M5 but, not easy to helicoil . Measure the depth of the thread and see if there is any thread at the bottom. Someone may have put a screw in too short.

The thread length is 25mm. It was a job I wished I had never started lol. sometime in the past some owner had decided to use an o ring and a copious amount  of black sealant, wich at first I thought was the old seal, however after trying to remove it realised it was black sealant cleaned it up as best I could put the new seal in but then the fitting didnt quite go in so tapped the seal as much as I dare until I could get the cable in with the original bolt for now but it is a tight fit only bonus is its not leaking yet!!!

[Trigger]

I use a special  tool to get them seals in, its called a gudgeon pin 

[ace cafe racer]

I use a special  tool to get them seals in, its called a gudgeon pin 

I had to resort to a 10mm long reach socket. Is 25mm the correct length?