1990s Mercury 90 HP Lower unit mounting nuts

[flylikechris]

Hello all,

I have a 1999 Mercury 90 HP 3-cylinder 2-stroke outboard. My lower unit mounting lock nuts are wearing down (5x), they're starting to round off. I'd like to replace them before it becomes a problem, and I figure the nylon is worn out by now. But I haven't been able to find the part number for these nuts. I'm curious where others are getting their replacements.

I found these on amazon: "Quicksilver 859116Q01", but they're listed for MerCruiser stern drives. I'm not sure if they'll work.

Or, if anyone happens to know the thread size, do you think it makes sense to just pick up some 18-8 stainless nylock nuts locally?

Thank you guys so much for your help.

 

[jimmbo]

I found the nuts that hold the gearcase on to be part #11-40140 M10x1.5 threads

 

[flylikechris]

Thank you! I'll give it a go and report back.