Automatic Project

Fuel and Oil Tanks


I searched through eBay for a Vespa automatica tank to start the process with. The auto tank has a much higher bottom to it, and it also covers where the plastic tool holder would have been on the old Vespa 90.

I thought that it just might drop right in but I was wrong. The opening in the frame in the Vespa PK series isn't as rounded as the older Vespa 90. The shot above shows about as far as it will go in without some modification.

Looking from above you can see the tail end is much too big. You can also see where there is a cut out in the original tank to allow for a special PK oil tank. The tank is very long and thin and has a visible oil low warning which pops out of the oil sight glass when the oil gets low. I managed to find one of these online and I plan to incorporate it in the same location. The idea is that each time you lift the seat to fill up, you'd see if the low oil warning was there.

I am learning how to weld and thought that although this might be a touch first project, I'd give it a go. The tank has been sitting for years and has no residual vapor in it so explosions won't be an issue. In order to shrink the tank down I cut the seam of the side to the top with a reciprocating saw. This will also make things much easier for the fuel sender device I plan to install too.

With some careful cutting I was able to overlap the cut seams and make the tank fit pretty well. The welding will be another story and I'll try some practice runs first.

With the top measured and in place I wanted to trim the square ears because they overhand the 90's tank opening. I marked them and removed them with a jigsaw .

Next, I installed the seat frame and marked where I would have to remove metal from the frame in order to get the oil tank in place.

Using a die grinder I removed just enough metal to allow the oil filler and sight glass to poke through, yet still allow the seat to go fully down. I also managed to make the original bolt holes on the front of the tank align with the 90's bolt holes.

More to come soon.....

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