Just to add some info, a friend decided to tear his new-to-him Vincent engine down as it seemed to have many issues, lack of power, oil burning, oil leaking.
It was supposedly built by someone with a good reputation, however many disasters in the waiting were found.
The engine crankcases and timing case had been sealed with grey Yamabond silicone sealer.
He found great long free strings of grey Yamabond inside the cases. This was from sealant squeeze out that had come loose over time.
Yamaha must have a method of applying exactly the correct amount so that squeeze out does not occur.
For the rest of us, a bit of squeeze out does happen, or you are unsure that adequate sealer has been used.
He was lucky in that none of the floating silicone appears to have plugged any oil passages, which is rather amazing given the amount of crap in there.
The anaerobic type 518 will be used on re assembly.
Glen