2003 25HP 2STROKE MERC THERMOSTAT HELP

Hey fellows out here i need a little help please if possible.I have a 03 25hp 2stroke merc that i want to change the thermostat on just for maintenance reasons.The motor is over a decade old and it doesn't look like it's ever been changed and for the little money it runs why not.

I have seen a few changed on you tube and most seem to do it the same,just pop off the bolts take the old gasket off and the old thermostat out and just put the new thermostat in and a new gasket and thats it.They never used any sealer or anything.Is this the proper way to do so?Do i need any special sealer or to grease anything at all?Just seems to easy but that is what i observed.

Any help would be great thanks.

If it has a paper type gasket, you won't need any sealer or grease.. Just make sure your sealing surfaces are nice and clean before putting it back together, and torque the screws properly.

How tight is tight enough for this deal.From what i saw on you tube they get the nuts to were they are tight but not crazy tight and then maybe a half of a turn more.I know not to over tighten them but i sure don't want to under tighten them also.I guess i will just have to use my judgement.

Also while i'm on water flow i may just check the water impeller.I have never done it though.Is there a special way with this motor to take the lower unit off besides just the 4 bolts holding it together,also does it need to be in foward n or reverse to do this water pump?After getting it off i think i can pretty much figure it out as it looks simple from all the videos i have seen on you tube.There is no 25hp 2stroke merc done on there so i don't know what it takes just to get the lower unit off.Any help would be great,thanks.

As for torque on the thermostat bolts, you really need a manual to get the specs. Baring that, I'd try snugging them down, starting the motor up and inspecting for leaks around the gasket. If it leaked, I'd tighten them down a little at a time until the leak stopped. But again, you really need to get a manual for your motor while you can find them and torque them properly.

For the impeller, you'll need to remove all the bolts holding the lower unit on, and you might have to disconnect the shift shaft linkage somewhere. Different model motors have different setups and I'm not sure what yours uses. Mine uses a spline shaft end so they just slip together but others use threaded couplers or other methods. For all the ones I've done, the manual says put the shifter in reverse before dropping the lower unit.