Winterization

**team supra** · 10-27-2020, 03:54 PM

Looking for thoughts on winterizing a 2018 300 XS OptiMaxx. The last two tanks of fuel have had stable in them. now for the winterization process , was wondering about the thoughts of just shutting the gas off and running motor out of fuel instead of using a separate tank with ethanol treatment in it. And running treatment through engine . Then just greasing fittings changing lower unit fluid and squirting oil into cylinders

**kellytheaker** · 10-28-2020, 09:03 PM

Supra - i was hoping to see what tech was brought up on the subject pertaining to the Opti - storage/ winterizing . I thought I had read here that Mercury does not support foghing oil into cylinders for storage .Hopefully someone chimes in on this and can help explain why or why not .
I quickly did some snooping around and found a link that Mercury stated not to use fogging oil in EFI or Opti - it can create a problem with the injector tip. They did state that the use of the correct oil can be used in the cylinders for storage .

**team supra** · 10-29-2020, 05:41 AM

Yes the manual states to use opti oil, 3 ml. Or so to squirt into each cylinder. My concern was the process of taking care of fuel system.

**kellytheaker** · 10-29-2020, 05:51 AM

Blake - from Injection Services may be a good guy to comment on fuel related -Opti stuff - he is inside this stuff more often and should be able to let us know what he knows on the subject .

**Dave Strong** · 10-29-2020, 09:13 AM

Stabilizer good, running out of fuel not. Those electric pumps don't last wrong when you run them out of fuel as needed for cooling and lubrication.

Dave

**InjectorService** · 10-29-2020, 09:54 AM

Fuel stabilizer and you are good to go. It wouldn't hurt to premix some 2-stroke oil in the fuel as well, keep everything lubricated.

**team supra** · 10-29-2020, 12:38 PM

I do have a few gallons of Klotz left over from our 260 motor I can add that to the fuel what ratio would you think. 75:1. Or 60 ish

**FMP** · 10-29-2020, 04:48 PM

Run a few minutes of avgas through it before shutting down for sleep

**InjectorService** · 10-29-2020, 05:35 PM

I would say 75 would be plenty. You just need a little to keep the pump and injectors lubed. Should help with cylinder walls as well.

**team supra** · 10-29-2020, 05:44 PM

Thanks again, I will run a small tank of premix using 94 pump and a shot of aces.

**FMP** · 10-31-2020, 10:45 AM

Can't beat fresh avgas with premix, shelf life within the system and additives for cylinder.

**Euroski** · 10-31-2020, 11:57 AM

Over the 10 yrs I had my 300xs I would treat the fuel before last run and run the tanks low. and follow the merc manual too.

**David** · 10-31-2020, 01:20 PM

I put the boat away with the tank full of fuel with stabilizer. The tricky part for is fogging the 200XS. I use fogging oil and the plastic 'straw' is too short. Does anyone sell longer ones?