1999 2stroke 90 modle# and head gasket question

[birdseye418]

I know I have a 1999 90hp 2 stroke. When the modle # was ledgable I was able to determin it was the C modle. now it can't be read of the motor. Anyone know what the modle # is?

Also found a little water on the #3 plug so I was told the head gasket was bad. I don't think I over heated the motor. Other than a bad gasket how could water get to the #3 cylinder? Gas is clean and have clean filters.
I pulled the head and the gasket was nasty and had some rust on it. Any tips/do's and don'ts in replacing the gasket? I do know the touque specs.
11fp then 22fp

[99yam40]

C90TLRX maybe depends on the motor specs.
Yamaha Outboard Parts

make sure the head and block are true and flat