4 Stoke Mercury 115

[ezcartdude]

Hello everyone Really like this forum. I appreciate the advice I recieved concerning having a cover made. I brought the boat in this weekend and the cover should be done by next weekend. My next questions concerns the 2003 115 4 stoke Mercury I have on my boat. When I bought the boat I did not recieve any manuals. What is the max safe operating RPM on this engine? It does not have a fuel/water saperating filter on it, I was thinking it would be a good idea to add one, What do you think. Also this boat was not run last summer at all, Looks like it has about 10 gallons of gas left in it that I am guessing could be about 1 1/2 years old. I took it out for a ride before I purchased it, It ran good, should I get this old gas out or just add some marine grade stabill and run it? Any body else out there have almost this same engine? Any thoughts or advice are greatly appreciated. Thank you

[HandymanHerb]

Welcome, if the gas small good and it ran good, it's probably some of the good gas before they screwed with it to kill mileage and engines.

I let the rest of the guys with 4 strokes fill you in with the rest.

[dockholiday]

Hello everyone Really like this forum. I appreciate the advice I recieved concerning having a cover made. I brought the boat in this weekend and the cover should be done by next weekend. My next questions concerns the 2003 115 4 stoke Mercury I have on my boat. When I bought the boat I did not recieve any manuals. What is the max safe operating RPM on this engine? It does not have a fuel/water saperating filter on it, I was thinking it would be a good idea to add one, What do you think. Also this boat was not run last summer at all, Looks like it has about 10 gallons of gas left in it that I am guessing could be about 1 1/2 years old. I took it out for a ride before I purchased it, It ran good, should I get this old gas out or just add some marine grade stabill and run it? Any body else out there have almost this same engine? Any thoughts or advice are greatly appreciated. Thank you

Think I would siphon out as much as I could, and just run it in my car. Maybe just using 5gal at a time till it is gone. Maybe some free manual download out there but here is one for about 15 bucks
http://www.outboardexpert.com/mercury1.html

doc

[oldmn19]

I have a Yamaha 90 4s, if it were mine I would drain it all out if you can, refill with fresh gas and Stabil! Also remove the engine cover and unscrew the clear plastic fuel bowl, which is a small water separator, check it for water, if none empty it and reinstall, don't loose the little float in side it. Use the old gas a little at a time in your car or truck as said above. This new gas is junk and goes stale very quickly! Always use some Stabil, its cheap insurance.

[slingshot]

ezcartdude:

Welcome to this forum, really good folks here. Congrats on your new boat and more importantly, congrats on the Yamaha you have with it. You see, Yamaha made your OB for Mercury during that year so your motor is actually a Yamaha F115, The manual for the Yamaha can be gotten off of the Yamaha web site. Max RPM for that motor is 6000, your motor has a rev limiter so you can't hurt your engine by over revving it. Engine oil is 10w30 in the winter or 10w40 in the summer (use synthetic). Oil filer is a Fram 6017A (about 1/2 the price of the Yamaha filter). I use AMSOIL 80w90 in the lower unit and it will take just under a quart. As for your gas, as someone else wrote, if it's running fine now then fill the tank with fresh gas and go out for a nice long run and burn it all up and refill your tank. However, I'd change all those fluids I just mentioned before you do that.

[ezcartdude]

Herb,Dock,Oldmn & Slingshot. My hats off to all of you for your help. Thanks especially to Slingshot for filling me on all the details of my engine. My brother-in-law has the Yamaha F115 on his 1850 Lund Tyvee Fishing/Speed boat and loves it, Has been a problem free engine for him. I hope mine goes as well. I never thought I would be able to find a boat with a bigger 4-Stoke EFI in the price range I purchased this for!

[FloterBoter]

what doc said, feed the old gas slowly to your truck, put fresh stabilized gas in your boat.
stabilizer stabilizes fresh gas, it's not meant to salvage old gas.
change the fluids as slingshot said. always check the lower unit gear lube for water and metal shavings.
i run techron fuel treatment once or twice a season. but that's another thread...