Hi guys, update time.
Got myself a near mint mid section and because it comes with a far better condition steering arm (not too happy with one that is on it now, very corroded, a problem with these engines) I'm going to take the powerhead off and rebuild. Have talked it though with a very competent outboard fixer and he will help me if needed, but says it's mostly just bolt off then on again.
This obviously means more work than before and includes undoing the 4 bolts that go DOWN from the powerhead as well as the 8 that go UP into it. All of the 8 bolts come away freely, but 2 out of the 4 (the 2 at the back of outboard) are a pig to get to. Any tips? see pic. This one is not too bad and should come away with a bit of heat treatment, but the other one is buried, looks like I'll have to take a few bits off the powerhead to get in.
Referring back to my first picture, I'll be needing 2 new gaskets for either side of the small section that connects the powerhead to the mid section (the bit that gets covered by the wee plastic apron). I assume that a local yamaha dealer will have such gaskets even if it is a 25 year old 1990 outboard?
Thanks for all the help again