Chainsaw Repair

i cant see pic right now. tank vent on 3450 is hidden behind left side crankcase. fuel line on top left of carb. if fuel line shrinks where passes through tank. fuel will seep by and run down tank. if brass tank vent and duck valve missing leak it will leak down the tank too.

When i took that pic, i think i was testing to see if it was the seam, by slowly pouring in gas until it got up to that point on the tank, then it started leaking... could ANY of the vents leak with only half a tank as it lays on its side?

i also wondered if you could get a soldering iron and seal the seam with ABS strips from elsewhere, and just weld it back together. that works good on other plastic tanks, they arent this thin though. The cement may be easier, as long as i can see the seam from the inside good enough.

I think you will find the tank is molded of "PP" (polypropylene) plastic and not ABS plastic. Most solvents or glues do not work on it.

Plastic welding works. You need polypropylene plastic as a filler material. Some people have used string trimmer line as filler rod.

i will try to weld it first, near where it looks to be leaking from. Im wondering if these seams progressively get worse, where the seam widens outward, making it worse. I really like this saw, a guy gave it to me, with a broke pull cord and muffler, and **** gas lines. It fixed right up and ive been using it ever since. I would hate to swap out gas tanks though, looks like the handle is built in. hope i dont have to take the tank off to weld any other spots.

Let us know how the plastic weld works out.   I am interested in the success of that kind of repair.