Due to personal issues with family sickness and death's, when the batteries in my 500 and 90 died, I just left them parked in the building for a little over 3 years. Now that I am finally getting back to normal, I decided to get them out and going again.

I know when I parked them, the 90 had almost a full tank and the 500 had about half a tank. When I got them out last week for fresh batteries, both tanks were bone dry. The good news is I use Seafoam. With fresh batteries and a quick fill up, I hit the starter button on both, they fired right up and they were running like a Swiss watch. It was just as if they were never parked at all.

If the gas can evaporate out of the tank, is there a chance moisture can also get in the tank easier? Any ideas other than finding an expensive billet aluminium cap with really good seal that might stop this?

 

your tanks are vented so a different gas cap wont make a difference. if they get warm from the outside heat they can evaporate the gas out as well as condensation can get in from the different temp ranges. try to always leave the tank full of gas to help prevent the condensation part.

 

That's right, I forgot about the vent. Good thing for Seamfoam eh lol.

 

Sometimes you get lucky. That was a long time for the gas to go bad before it evaporated.