If anyone has a Volvo D1-13, D1-20, D1-30 apparently it's not uncommon to get a small oil leak from the throttle input shaft.
Ovlov will quote north of $1k to fix and insist on taking the whole front of the motor apart to remove timing cover.
I saw them and showed them schematics about an easier way that meant only undoing 1 nut and 4 bolts but when the mechanic went to the boat and after inspecting he said it couldn't be done without removing the timing cover.
At this point I told them I would do the jib myself! I have successfully completed the job in the way I always thought