Looking to purchase and older 9.9 outboard

[Russ C]

I am looking to get some opinions from some of you that may be in the know. I am looking to purchase an older (1991) 9.9 outboard that has not been run in 15 plus years. It was just recently started and ran fine but with 15 year old oil. Could this be a problem (running it with old oil) for this motor in the future?
Thank you in advance Russ C

 

[cougar1985]

Re: Looking to purchase and older 9.9 outboard

russ, oil in of itself is millions of years old!so oil out of a can lets say 15 years old would not really be a problem.not trying to be a smart *** but oil is really old,just that its refined and added to.

 

[redfury]

Re: Looking to purchase and older 9.9 outboard

I am looking to get some opinions from some of you that may be in the know. I am looking to purchase an older (1991) 9.9 outboard that has not been run in 15 plus years. It was just recently started and ran fine but with 15 year old oil. Could this be a problem (running it with old oil) for this motor in the future?
Thank you in advance Russ C

The only problem with old oil would be if there was a significant amount of water that had mixed in with it years ago and now had a chance to settle....suddenly anything at the very bottom of the oil is now sitting in water as oil will be on top, so if you are speaking of the oil in the lower unit, then you've taken the chance that lower unit bearings have been run with basically water lubricating them.

Beyond that, old oil isn't a problem unless it was really old before it was set aside. The only thing that is going to damage the properties of oil in a 2 stroke outboard are going to be contamination and heat. If the lower unit overheated, then you have bigger problems anyway. Other than that, it's going to be an issue with oil contaminated by water.

Oil in a 4 stroke is another matter as combustion gasses mix with the oil and can create corrosive elements to form in the oil.

 

[Frank Acampora]

Re: Looking to purchase and older 9.9 outboard

Lower unit oil is so cheap, why not just change it on general principals?

And if it has a little water contamination, it will emulsify in with the oil (tan to white milky color) and lubricate just fine, as long as you don't try to run it all season--or multiple seasons. Again, lower unit oil has significant corrosion inhibitors. Even if there is a little free water, the oil binds up free oxygen so as long as the lower unit is not opened, rust will not occur on the steel parts. (rust is ferric and ferrous oxides--it's not water that makes rust, it is oxygen combining with iron and forming oxides.)

But again Lower unit oil is cheap--so are water pump impellers. Change both of 'em on general principals--cheap preventive maintenance and the engine will probably last longer than you..