Noob Motor Questions

[TMF89]

Hey guys, I have a Yamaha 115hp Four Stroke, and I want to change the oil and possibly the spark plugs. Now changing the oil on a marine motor is talking about the gear oil right? Not regular motor oil? What's the difference and when do I use them, marine-wise? Also does anybody recommend any specifics? I was thinking of just going to the auto store and getting whatever they had for 10w-30w marine grade gear oil. Suggestions? And on plugs, how do I know when to change, and any specific recommendations on what to change to? Thanks guys.

[Het]

On a four stroke, you will have 'motor oil' as well as 'lower unit oil', whereas a two stroke's motor is lubricated by pre-mixing the oil with the gas, either manually, or by direct injection of the oil.

I always use the oil recommended by the manufacturer. If I were you, I would check the manual for the recommended weight of Yamalube, and use the amount specified. While you're at it, check for any filters that need changed, and change the lower unit oil while you have your tools and rags out.

[TMF89]

Well everything I've seen has said 10w-30w, so I think I'll go with that. I have one dipstick on the motor and one oil cap on the top of the port side. The dipstick is on the starboard side. Are those fort motor or gear? How much of each should I use? I might have lost the manual some time ago, lol.

[Jim Almquist]

Your gear oil will be in the lower unit. You will see two screws on the starboard side. If you want to check it you would use a squeeze bottle of 90 weight gear oil and insert it in the lower screw hole and then pull out the top screw and squeeze in gear lube till it comes out. If it is milky you have a bad seal. If it is clear you are good to go. Put back in the top screw and then put back in the bottom screw.

On my 60 4 stroke Yamaha there is a bolt you need to remove with your motor in the up position to drain the oil. It is about half way down in the back center of the motor. Mine has a rubber tube with the bolt up in the tube. I thought it was a size 14 metric socket. When you pull the bolt no oil will come out till you lower the motor. On my 60 you add the oil through the dipstick opening but yours may very well be different because of the size of your motor.

[delcecchi]

What once was lost, now is found...

http://www.yamaha-motor.com/outboard/service/viewmanuals/outboard_manuals.aspx

[jac714]

If I were you, I would go to Yamaha's web site under parts and service there is a menu choice on the left for View Owners Manuals and find the one for my motor and download/print/read it.

You don't want to use the wrong lubricant in the motor or gear case, it could end up costing thousands or blowing up your motor.

[Ufatz]

Well everything I've seen has said 10w-30w, so I think I'll go with that. I have one dipstick on the motor and one oil cap on the top of the port side. The dipstick is on the starboard side. Are those fort motor or gear? How much of each should I use? I might have lost the manual some time ago, lol.

Without being too judgmental, you REALLY need to get the manual for this motor, or at least go to the Yamaha site and learn more about your motor.You must get some BASIC knowledge about the motor you have so you understand how it works and why. This particular engine is one of the more dependable motors on the market and fairly easy to care for.....but you just GOTTA know more about it.

[Sonicrunch]

Hey guys, I have a Yamaha 115hp Four Stroke, and I want to change the oil and possibly the spark plugs. Now changing the oil on a marine motor is talking about the gear oil right? Not regular motor oil? What's the difference and when do I use them, marine-wise? Also does anybody recommend any specifics? I was thinking of just going to the auto store and getting whatever they had for 10w-30w marine grade gear oil. Suggestions? And on plugs, how do I know when to change, and any specific recommendations on what to change to? Thanks guys.

10w-30 gear oil???

[hookjunior]

Have you considered having the work done at a dealer? If you're really that unfamiliar with it it might be worth paying somebody just for the peace of mind knowing that it's done properly.

[TMF89]

Like I said, sorry for the noob questions guys. 10w-30

motor oil, and posting on here is part of me researching it. The gear oil I'm holding off on for now, I haven't been able to figure out exactly what it needs and I know that can cause major problems if messed up. The only other issue is a very small amount of gas was left in from last season with no stabilizer fluid. Less than 1/8th a tank, probably closer to 1/16th. I'm thinking just adding quite a bit of good gas to dilute it, should I add some treatment fluid as well? I know Stabil's the standby, but I saw some "fuel system cleaner" stuff at the store as well, what would you guys do?

[delcecchi]

By now you have read the fine manual, as in RTFM, haven't you? It should tell you the weight and grade of oil required. Also the lower unit lube and how to check and change it. (they sell small pumps for putting it in)

Seriously, if you have those kind of questions, read read read. And have it serviced at a dealer until you know what you are doing.

[SkunkedAgain]

Follow everyone's advice about the oil, and when you're ready to do it, have a knowledgeable friend there. It's small insurance that could make a HUGE difference.

As for the gas, don't worry about it. If you've already been running the motor this summer it's no big deal. Add some fresh gas and you'll be good to go. Stabilize it before putting her to sleep for the winter.

[Northlander]

Just fill the tank with some good premium gas and you should be fine. Changing oil, plugs, lower unit and oil filter is super easy on the F115. I have been doing mine for 7 years now. One trick I do when changing the oil is I tape a plastic garbage bag on the lower unit under the drain plug and make it a little chute for the oil to drain down. Its much cleaner this way.

Where are you located maybe someone could come show you the basics. Buy yourself a good lower unit lube pump. You will have a very hard time trying to do squeeze tubes into the F115 although it could be done in a pinch.