I don't think that would be legal Norm to use a mower fuel tank in a Ultralite aircraft, as far as I know there are regulations for what you can use.
I wouldn't be spending time and money to repair a tank when I can just fit another tank quicker than repairing one and if the repaired tank ever leaked and someone caught fire etc they can file a lawsuit against you if they can prove you repaired the tank. Different story if you're repairing the tank for yourself to use a mower.
I picked up a lawn beetle today and got it running ,eventually the smoke cleared and it ran well then I cut the mower up and in the bin it went ,a few years ago I would take 3 mowers to make one but these days it would cost me $20. more than what I can sell the mower for ,if I add up the cost in fuel to pick up 3 mowers and parts to do the service I'd be minus $20 when I sell the mower for $50.At least I can use the wheels on a Victa 18.
