Interesting find...

[FabricGATOR]

I was cleaning up and I saw some debris under one of the lower engine mount cheek plates. When I removed it, I found the motor mount dampner bolt head had rusted away. There's still just enough to retain the bonding wire terminal end.

So I'm going to order some bolts. I inspected the other side and it is in pristine condition. I removed / inspected the port engine too and found the same situation. Interesting. Both of the port bolt heads on both motors are gone. The rest of the hardware appears to be clean, just the two portside bolts on both engines. Electrolysis?

Item 20 BRACKET 2 $18.21 a piece...

Year 2000 SX/LX150TXRY

[rodbolt17]

you may find its more trouble than its worth.
the midsection must be removed from the steering bracket to remove the bolt and mount assy.
means the powerhead,lower pan and lower unit must be removed to access the upper mounts.

[exeter27]

What you describe is how I came into my first Yamaha outboard - and F60. The previous owner had the same problem as you - where the upper mounting bolts (that go through the upper damping mounts) - had rusted away and failed.

I did as rodbolt mentioned earlier in this post - removed the powerhead to replace the bolts. Unfortunately, it was worse because the PO ran it enough after the failure to cause the mount on the upper part of the steering tube to be worn away - so had to replace that too. Founds parts on eBay for that - so it took out some of the sting.

Those bolts aren't cheap - around $20 a piece! You'd think they'd last forever for that price!

[FabricGATOR]

These are the lower bolts at the very bottom of the pivot tube, just above the lower unit.
It looks like I should be able to remove the dampner retention castings and the cap nuts on the bolts.

Am I fooling myself? Am I going to have to unmount the powerhead to access these bolts?

No, say it isn't so...

I guess I could just run them until they depart the vessel and descend into the big blue toolbox. That wasn't really my plan.

[rodbolt17]

typically on the lower mount there is not enough clearance to withdraw the bolt.
typically you insert the bolt into the mount then insert the mount into the casting then assemble the casting to the steering tiller.

[exeter27]

I misunderstood. The bolts I replaced were the upper bolts. As rodbolt says, to pull the lowers you need to create clearance. You do that by backing out the uppers. To loosen up the uppers, you need to loosen nuts - which is possible if the bolts don't spin. Then when you reassemble you need to retighten nuts hoping bolts don't spin. To prevent spin, you need a wrench - but the engine is in the way. I'd try it as you have nothing to lose. If they spin, you remove block. If not, you got lucky.

Remember to support the engine as the four bolts you are loosening/ removing support the whole thing!!!!!