how long can 2 stroke oil sit?

[inohv8]

I aquired a boat/motor/trailer that has not been run for 8 years.. After a major cleanup and maintenence.. I beleave it's ready.. however, when I tested it with the muffs, I ran a rich mix to make sure oil got in the engine ( from a seperate tank).. Now saying that, the engine is a 100 hp Merc 1989 with the searay label on it, There is a tank on the engine that is almost full with 2 stroke oil, I don't know what make or the quality.. My question? does oil go bad considering it is probably over 8 years old? would it be to my advantage to drain it and re-fill? the tank holds at least a gallon and some, the fuel tank is a built-in that has been cleaned out and ready to fill. My judgement says start with new oil, Can some of you give me your opinions?<br />Thanks..<br />Inohv8

 

[rickdb1boat]

Re: how long can 2 stroke oil sit?

My thought is that the oil that's in the reservoir could be comtaminated with water(Condensation) or other substances from sitting so long. I would drain it out and refill with new. No sense taking chances now..

 

[inohv8]

Re: how long can 2 stroke oil sit?

I was hoping someone would suggest that.. Now the next question.. synthetic or real? and why? if nothing other than ash and environmental issues...<br />thanks for your feedback

 

[rickdb1boat]

Re: how long can 2 stroke oil sit?

That's kind of a personal decision. Theres been alot of debate on these forums as to which is better and no one seems to agree on a difinitive choice one way or the other. If going synthetic, I believe that Amsoil is the best bet, as they have the most experience in the field. Either way, if you maintain the engine properly and mix the oil to the proper ratio, I don't think you can go wrong. Outboards ran for YEARS on good old petrol oil....

 

[inohv8]

Re: how long can 2 stroke oil sit?

Thanks for the comeback Rick. I will probably go with the sierra since I can get that easily.. regarding the proper mix? well, I will pretty hard to regulate due to the fact that the engine figures out what it needs.. I am really scared of that.. and my built in tank holds about 20 gallons.. I can only guess by the amount the level goes down, that it is working.. if it is plugged or not working to inject it, then I can kiss my engine good night...<br />I think a good choice would be to run a 5 gal. tank with a mix and see if the level goes down on the built in tank.. I suppose the only thing that can happen is that it will smoke like crazy.. But at least I will be able to see by the site glass if the engine is drawing oil..<br />I really appreciate your comeback and your valuable info. <br />Inohv8

 

[timmathis]

Re: how long can 2 stroke oil sit?

I'm not telling you to do so but alot of people bypass the oil tank and pre mix. That would be up to you.

 

[inohv8]

Re: how long can 2 stroke oil sit?

I've done that on some other engines, mostly other peoples. but when it comes to mixing a 20 gallon tank? ouch.. I kind a like having all the tank(s) below the floor, but always felt safer with the 5 gallon tanks above the floor.. I really don't have a spot to put the portable tank (out of site) as the rear seating area is above the battery, ice box and extra storage (to small for fuel)and . Behind that is a very small area due to the swim platform.I already rebuilt the floor, so removing the built-in tank and making a storage area for portables is out of the question right now I'll monitor the consumption of oil and go from there ( I suppose).. Thanks for your feedback.

 

[rickdb1boat]

Re: how long can 2 stroke oil sit?

Merc. injection is very reliable. Not to worry if maintained. Run 50:1 pre-mix until you verify the oil level dropping in the tank..

 

[inohv8]

Re: how long can 2 stroke oil sit?

I have a 40:1 mix in one of my tanks, which I am slowing using up in my snowblower (lots of smoke for sure). I will mix up a 50:1 mix when ready.. thanks very much..

 

[LubeDude]

Re: how long can 2 stroke oil sit?

Originally posted by inohv8:<br /> I beleave it's ready..

Are you sure?<br /><br />Have you replaced every single peice of rubber or plastic hose under the engine cowl?<br /><br />Looked at every wire.<br /><br />Changed plugs.<br /><br />Fuel pump.<br /><br />fuel filters.<br /><br />Water pump.<br /><br />Changed the lower unit oil.

 

[inohv8]

Re: how long can 2 stroke oil sit?

I beleave it's ready.. <br />--------------------------------------------------------------------------------<br /><br />I don't remember putting the I beave it's ready in, however please check your questions below<br />Are you sure?<br /><br />Have you replaced every single peice of rubber or plastic hose under the engine cowl?<br />HOSES ARE SOFT AND CLEAN INSIDE. BUT i DID REPLACE THE OIL INJECTION LINES AS A MATTER OF COURSE.<br /><br />Looked at every wire. COMPLETELY<br /><br />Changed plugs. CHANGED PLUGS FOR SURE<br /><br />Fuel pump. WORKING PROPERLY BUT CHANGED DIAPHRAM ANYWAY..AS A MATTER OF PRECAUTION<br /><br />fuel filters. I FOUND 3 FUEL FILTERS ONE IN ONE FOR ENRICHMENT AND ONE FOR ENHANCER.. ALL PASSING CLEANLY.. ALSO INSTALLED A WATER SEPERATOR/FUEL FILTER.<br /><br />Water pump. ALSO CHANGED AS A MATTER OF SAFETY.<br /><br />Changed the lower unit oil. WHEN i CHANGED THE WATER PUMP<br /><br />i HAD THIS TIME BECAUSE OF THE COLD WEATHER UP HERE AND FINISHED THE WORK ON THE INSIDE OF THE BOAT.. SO THE ENGINE GOT TOP PRIORITY, IT FIRED UP, FOUND A PLUGGED TELTAIL LINE, SO i REPLACED ALL FUEL LINES AND EXTERNAL WATER LINES, FIRED IT UP AGAIN THEN FOGGED IT.<br />--------------------<br />Its confermed: Bass Fishing is a mental illness!

 

[rickdb1boat]

Re: how long can 2 stroke oil sit?

Sounds like you've been pretty meticulous. Good job looking after some of the small, but important, stuff....

 

[inohv8]

Re: how long can 2 stroke oil sit?

Thanks.. I am anxious to try the beast.. but being winter here, I have another 2 months at least.. The engine is on a stand right now so I could work on it. I had to re-work the tilt and trim anyway (bushings and re-built pump).. aren't hoists wonderfull.<br />thanks again.

 

[Texasmark]

Re: how long can 2 stroke oil sit?

So on the question of oil going bad; most of it has only been in the ground for a million or so years!!!! Not talking about what can contaminate it; but oil per se going bad.<br /><br />Mark