Unwinterizing yamaha 250 2 stroke

[John Rogers]

My parents are finally putting there boat back in after almost 2 years. What things need to be done for it to be unwinterized. I know I am replacing both batteries. The boat has almost a full tank of gas but there was stabliezer put in, I was told it may not run the best but it will be ok. Changing the spark plugs. Should I replace the lower unit fluid? The motor at best has 30 hours on it if that. OR should I just check it. Thanks for the help. I am very dumb when it comes to this crap

[Proheat]

John- When the motor was winterized- was the lower unit lube changed. Thats when it is supposed to be done on account of water or moisture possibly being in it. As far as the gas- there isn't much you can do since it is almost full- You could top it off with Premium gas so it will dilute with the older gas and help it run better. Was the water pump impeller changed when it was winterized- if not, I'd suggest a new one- especially after sitting 2 years drying out. My opinion with the spark plugs is- see if it fires up and runs. after running a fuel tank through it, then change the plugs for the season. If not, then change them first. I was just thinking of them fouling out with old gas.

I know that my mechanic recommends having the fuel pump diaphragm replaced every 2 to 3 years- you might want to do this too, especially since it sat a little while.

Hope this helps. Maybe someone else will add here.

[Glenn W]

John, as I recall you are not the shade tree machanic type
In any event, I am a bit anal when it comes to fresh gas in my boat. Even with Stabil, it will last at most 1 yr. Gasoline looses it's octane which makes things gum up. Worse is the spark knock on the pistons with old gas-- not good at all on a 2 cycle. What I do and would recommend you do, is pump the old gas from the boat to your car ( it won't hurt your car just put a half tank at a time) To pump out fuel, go to an auto parts store and buy a generic electric fuel pump, 20' of fuel line hose, 2 clamps, a roll of 14 gauge wire, and 2 alligator clips. unhook fuel line on boat at squeaze bulb and connect to portable electric fuel pump, put other end in car gas tank filler. connect wires to a battery ( make sure battery is away from fuel as you don't want a spark blowing up half of southern Maryland)-- presto. you will find you use this pump alot--- plus it is a source of free gas from mom & pop's boat ( I had to lock my pump in my tool box, as my 17 yr old son soon figured this trick out).
See if you can find the service receipt when it was winterized to see if lower unit was changed. a new water pump is a good idea as time may have made the rubber hard and brittle but its probablly ok. I agree with proheat that you should not change the plugs intil after a tank or 2 of fresh gas. I disagree with the use of Premium gas as this burns at a higher temp than 87 octane and is not recommended by Yamaha (tough on those alum pistons).
With fresh gas in it take it easy for a little while then run the piss out of it for a while to clean things. I am also a believer in Seafoam ( avalable at most auto parts stores) put in the fuel to keep carbon build up down .
If batteries are still charged they may be ok, if they are dead-- they likely froze during the winter and definatley need replacing. Don't forget to check and tip off power steering fluid and trim fluid.
Good luck

[74Formula233]

I have to agree with Glenn here.....2 year old gas in an expensive outboard isn't a good idea. I'd pump it out as well.

Also agree on octane....don't "over-octane".....use what the manufacturer recommends. Some require Premium, most don't.

And Seafoam? I like it! It's a REAL "fuel cleaner" unlike the .99 cent bottles you find at Walmart. NAPA carries Seafoam, probably most other good auto parts stores.

[TommyTuna]

I have to agree with Glenn here.....2 year old gas in an expensive outboard isn't a good idea. I'd pump it out as well.

Also agree on octane....don't "over-octane".....use what the manufacturer recommends. Some require Premium, most don't.

And Seafoam? I like it! It's a REAL "fuel cleaner" unlike the .99 cent bottles you find at Walmart. NAPA carries Seafoam, probably most other good auto parts stores.

advance auto parts carries it $2 cheaper than NAPA and occasionally its on sale! (where I buy all of it)