Nautique 216 Rear Seat and Ballast Question

[dkimball]

I have completed the winterizing of the engine of my new to me 2003 216 but am having trouble with getting the ballast tanks to winterize. I tried using a fake a lake with a buck and hose to suck up the antifreeze but wasn't able to get it to suck up enough to actually pump it out of the drain pumps. Any other ideas on how to winterize these? I have heard of pouring antifreeze through the vents but I am not sure which one I would use. Otherwise it looks like I will have to follow the steps in the manual which required the seat and floor to be removed. This brings me to my next question. Where are the straps that hold down the rear seat so I can get that removed? Thanks.

[GMLIII]

I believe it is held down with 2 pins which can be founds behind the rear seat cushions

[dkimball]

Luckily I was able to get the suck up method to work with the ballast. However I would still like to know how you remove the back seat. The only cushion I can remove is the center one. The bottom of the seat isn't attached to anything upfront but must be attached somewhere in the back. There is really no access to find any pins or anything holding it down. Any other ideas on how to remove the seat? Thanks.

[GMLIII]

Luckily I was able to get the suck up method to work with the ballast. However I would still like to know how you remove the back seat. The only cushion I can remove is the center one. The bottom of the seat isn't attached to anything upfront but must be attached somewhere in the back. There is really no access to find any pins or anything holding it down. Any other ideas on how to remove the seat? Thanks.

The pins should be located behind the seat cushions which are screwed down(the left and right cushions) and the not behind the middle. They are pins with circular pull rings attached to them.