Stihl 029 - Gas Tank leak.

[Drifthopper]

Stihl 029 - Gas is dripping / leaking from one if the fastener holes where the black handle gets secured to the saw with.

This is my dad's saw, I used last weekend, ran two tanks of gas thru it, no issues, then went to fill up again, and gas was steadily dripping from under the saw.
I originally thought it was the gas line, but upon further inspection ( and disassembly ) ... the tank has a hole in it.
Somewhere along the line, Dad must have lost the socket head torx fastener that goes in there, so he put in a pointed, course thread sheet metal screw.
I have used the saw before, but last weekend, the point of the screw punctured the tank.
I couldn't get a picture, but looking in thru the fill hole, you can see where the plastic is cracked / spider webbed.

Any suggestions on how to fix it..?

And...... is this saw suppose to have metal teeth for gripping the log..?

 

[Jon1270]

Short of rebuilding the saw on a (broken link removed to http://www.ebay.com/itm/Stihl-MS290-029-039-MS310-MS390-new-HD-engine-housing-replaces-1127-020-3003-/322229822460?hash=item4b0664e3fc:g:inQAAOSw-itXswjH), your best bet is going to be plugging it with epoxy. I'd very carefully clean the inside of the screw hole and the area inside the tank where it pokes through, because oil residue from the fuel will prevent adhesion. A q-tip doused in alcohol would probably be a good choice for cleaning inside of the hole.

I'd be tempted to use the (correct) screw, assuming it will thread in properly, as a piston to drive a blob of JB Weld in to where it needs to be. Some would extrude into the tank, which you could then spread around with a small tool by reaching in through the filler opening. You would have to drive the screw into position and leave it there until the epoxy was cured, because backing it out while the glue was still soft would suck the glue right out of the hole you're trying to fix. Hopefully a couple of coats of paste wax on the screw threads would prevent the fastener from being permanently glued to the tank.

 

[jetsam]

You could also tap the hole out to the next size up (easy on the plastic tank, be very careful on the aluminum bits), and put a machine screw back in.

Get some fuel rated FIPG to blorp on the screw threads for maximum liquid tightness.