What year is this motor

[Gateswm44]

I have a mercury 40hp 4 cylinder 2 stroke. I’m assuming it’s an early 90’s model but the serial number is not present. I’m trying to find a new tilt/trim unit for it.

 

[GA_Boater]

Welcome aboard, Gates.

Year of the Merc isn't important since the motor doesn't appear to be a TnT motor and you have a CMC aftermarket tilt and trim unit.

What's the problem with the tilt and trim?

 

[flyingscott]

Look on the block for the serial #. GA is correct that is an aftermarket unit.

 

[Gateswm44]

That CMC is more or less a transom extension. It doesn’t have trim on the bracket. The motor still has the stock trim unit. The trim was leaking fluid when I bought this rig so I replaced the seals in piston assembly. Doesn’t appear to be leaking anymore and works perfectly until I run faster than an idle. Once I’ve gotten up on plane and start to trim it out it only comes up so high before falling down. If I hold the up button it just comes up then down over and over like it isn’t strong enough to raise the motor under a load

 

[Gateswm44]

You can see how it’s set up a little better in these pics

 

[jimmbo]

You really need to get the Factory Manual for that engine, and that will require the Serial Number. Have you looked on the Cylinder area of the Block for what looks like a Welsh Plug, with Numbers on it?

 

[Gateswm44]

These are the only numbers I can find.

 

[jimmbo]

You need to look for something like this

 

[Gateswm44]

Found them. Thanks for all the help.