'05 Opitmax 250xs general questions

[gregpro50]

I just bought a boat with an '05 Optimax 250xs. It is not the Pro-XS it is the one built by Mercury Racing. I know nothing about these motors other than it is supposed to run 91 octane. The next newest motor I have ever owned was an '86.

Do the Mercury racing motors take a special oil other than the optimax oil?

Does the lower unit take a special gear lube?

What is the difference between a regular 250 optimax, a 250 pro xs, and a 250xs?

Are they generally supposed to be reliable motors? The one I have is supposed to have under 100 hours and was owned by an older gentleman who seemed to take really good care of everything. He said 99% of the time the boat was run under 40mph.

[DRHOBACK]

I have 2 of same year, same model. Only major issue was sportmaster gearcase, pushed shiftshaft seal out and ruined internals. Owners manual says Merc Premium Plus 2 stroke oil. If it is sportmaster it takes Hi Prformance gear oil(green oil). As for the difference I know XS has solid motor mounts, not sure about other differences but think it turns a little higher RPM than other two. They come in a single ram trim(HD) and 3 ram trim(standard duty). Mine have about 170 hrs.

[gregpro50]

I'm confused by the oil recommendations. The manual says premium plus tc-w3 but the dealer says to use Optimax dfi oil which is not tc-w3 compatible. I know the previous owner used dfi oil.

[vnemous]

Mercury came out with a bulletin in 2010 that you should only use DFI oil in the opti contrary to what the manual said.