I'm reassembling my VST and cannot remember what I previously used to help seal the O-ring. It is white and dried like RTV would. I searched my goodies bin and can't find anything that is fuel safe and white. I'm sure I got the info. on what to use here, but it doesn't seem I wrote it down, nor can I find the info again when I searched. One of those things I said "I'll always remember that" and now here I am.

Does anyone have an idea of what to use or what it would be?

Thanks for your help,
Keith

Been a while but I think I didn't use anything but the O ring. That said fuel will slosh around a bit, but the fuel level doesn't come up to the ring and there is no pressure, so like a carb bowl. I could go out to the shop and find my old VST and pull the top to see if it looks like I did use anything.

Why do you need something above and beyond the O ring?

O-ring lube or grease?

Peace of mind when there's a tub of fuel hovering over a hot engine held by 1 bolt and a cover that isn't bolt through. If any screws loosen in a vibration prone environment at least there's adhesive present as a stop gap.

I wound up going with Loctite 565 which is a fuel safe pipe thread sealant. I have 562 in the box and that's what I probably used last time by color ID;however, I noticed in my latest research it simply says diesel safe.

I used no sealant on mine. Bought a new O-ring and dabbed a little Loctite on the perimeter screws. The OEM had no sealant I could see, BUT they did like their Loctite.

the new oring comes in a kit ONLY for the past x amount of time.

New oring is highly recommend cause you can run the risk of air leaks and or fuel leaks. Leak air can damage the engine over time and or cause running issues - leak fuel and possible ka boom.

test fit. See if its too large/ stretched. If so replace with a new one,which is usually not necessary. We can usually shrink it a little by placing it in the freezer for and hour. Then install with bellows cement. Good luck