I am trying to remember if the tank should be considered full at 3/4 volume or at a given level. Any council appreciated.
+1 on 3/4 full. The air expands as the fount warms up and the pressure assists the fuel going to the burner. If you have insufficient air in the tank a partial vacuum gets created as the fuel is used up. This might not affect the first burn, especially if it is a short one, but will be noticeable if you don't remove the flller cap to equalize the pressure the next time you use the stove. Regards John
Thank you. Taking a close look inside the tank it appears a good visual indicator that the tank is "full enough" would be level with the bottom of the tank fill.
The way the fill is designed an air pocket is always left in font. I generally fill till I spill. I don't always intent to spill, but it always seems like it does. And stove works fine.
An odd array of opinions and reasoned speculation, given that everybody providing an answer to this thread is a subscriber with access to the library of original Optimus instructions. If only you'd all bothered to take a look at the manufacturer's recommendations... ...you'd discover that over the years Optimus have instructed: "Not more than 3/4 full" "Not more than 2/3 full" "Fill the tank"
probably takes into account that on many (but not all) stoves, the filler port is a short tube that goes down into the fount. If you fill up with the tank on a flat surface the air above the bottom of the tube gets trapped preventing over filling. regards John
From various bits of paperwork, and noting that 2/3 to 3/4 will matter very little in this context. Tony