1995 15hp 2stroke merc maintenance

[boater1234]

I just bought a really nice clean 1995 15hp 2stroke merc,besides checking to see if it has great running water out of the pee hole and making sure the thermostat is opening up properly is there any other maintenance i need to do to it?I am changing the plugs,i just changed the fuel filter under the cowl as well as all the fuel hoses and coolant hose to the pee hole,if everything seems to work good i figured i am going to run some really good stabilizer through the gas called k100 as well as ring free from yamaha and i am going to run the engine a bit richer the first tank because i don't know how long it's been since it's been run and i want to re lube all the internal parts with just a bit extra oil then go to the 50:1 oil ratio,i'm also using 100% synthetic tcw3 oil.I want to keep the fuel system as clean as possible with a new tank and line.

If i'm doing something wrong or i need to add anything to this please chime in,thanks.I don't know how many parts are original or have been replaced but it is really a clean motor and i'm going to start it soon here.The compression is a dead even 120 on both cylinders so i know that's ok.

Just a curious question:would it make sense to use one tank of ethanol fuel because i know it's a natural cleaner and would clean the entire system if there was any minor issues,from what i have been told it runs really good and idles smooth but i will find out later today or tom.I normally use ethanol free fuel but i have no idea what's been used in this outboard.

 

[Nathan Bond]

Probably a good idea to change the lower unit oil. And don't use ethanol fuel in it, it's hell on a lot of the components in the system.

 

[boater1234]

Ha,forgot to mention the lower lube change included.That is just a for sure thing even if it looks like new the lube, i only use 100%synthetic ROYAL PURPLE lower unit oil.I think that is by far the best stuff around imo,yet pricey it lasts me over a yr and a half for $20,worth every penny to me just in case any water would happen to enter the lower unit.I know allot of people who have had some leaks in the lower unit and just change the lower unit oil with this RP every 4mths and it still works great with water intrusion,of course i would never do that unless i was in a jam at the time and couldn't afford to get it fixed that very moment.People claim it actually adds a few hundred rpms to over all top end,i can't say i have noticed that but who knows.

If the motor runs really well and pumps water excellent and idles great do you guys still think i should mess with the water pump or thermostat?My local marina told me to just leave it alone if it all works well and i do trust them as i have gone to them for over 15yrs but it's always good to get others opinion.