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Custom Fuel Tank


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When I put that 11.5 HP monster in my 707, I had to cut the fuel tank in half and weld a steel plate to the open end.  It looked like a Jr High metal shop project.  I finally got around to fabricating a new one.  

101 is the modified metal tank.  Notice the steel plate welded on the botom side (as it sits in the vise).  In this pic, it is all waxed up, ready for a coat of resin and fiberglass.  102 is the first layer of fiberglass in what will be the mold.  103 I cut out the metal filler spout for use in the final product.  104 is the finished mold.  I had to patch the opening from where the filler spout was removed but it came out nicely.  105 is the first part as it sits in the mold.  I had to make two halves.  One half will hold the filler. 106 is the first positive being seperated from the mold. 107 I used a block of 2x4 to trim the sides of each half.  108 I notched out for the filler neck and glassed the filler to one side.  109 I used JB Weld to bond the two sides because I wanted to make sure the seam didn't leak.  Maybe redundant, but there it is.  I sanded the JB Weld down and but a couple layers of FG tape around the edges for extra strength.  110 I coated the inside with Gas Tank Sealer and 111 painted the outside with a rattle can.  It now looks like a Jr High fiberglass shop project.  What the hell. 

The polyester fg resin I used is affected by ethanol.  The gas tank sealer is supposed to be ethynol resistant but I will be careful to use only non-ethyl gas as an extra precaution.

Cost was $100 - $150 but I had fun.  If I had to do it over, I could do it cheaper but there it is.  It holds about 1/2 gallon and fits right in right where it belongs.  













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Hello, that is an amazing thing that you have done . I am impressed

I had a 707 with an 11 hp briggs , I modified the firewall ( the gas tank support and battery area)

 I cut the firewall in half and rotated the U shaped piece  180 degrees  and re welded it, to gain a 1\2 inch that I needed. 

by making the gas tank fit, I made the battery space too small.   I ended up using a motorcycle battery for it .

the blue line shows how mine was 

Thanks Ken in Mi


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