Just thought I would Post an easy way to increase the Capacity of your gas tank by about a 1/2 gallon for free. I did this on my Zilla about 15 years ago with great results. It can make the difference between a fun day and a long long walk.
How TO:
Make sure the tank is mounted in place, drained of gas, and have a cap and petcock that don't leak.
Insert into the end of your fuel cap vent hose an air valve. I just cut one from an old tube. Close your petcock and disconnect fuel line from carb.
Fill the tank almost full with boiling hot water. Screw the cap on and use a bike pump to pump up pressure in the tank. I think I did something like 5 lbs or so pressure. Now Go to bed and let it cool. The next day drain it and repeat the process a few times. I suppose if you get too carried away you could seriously distort the tank and have problems with the plastics fitting.
I don't recommend trying it with the tank off the quad or I doubt that mounting holes would ever line up.
Hows it look when all done. For a lt500 1/2 gallon is a big difference.
To look at it mounted with plastic you cant tell any difference at all. Looking at the tank off the quad it looks slightly bloated. A slightly snug fit where it drops down over the frame tube.
We take some long rides out in the utah desert and its piece of mind having a little more fuel.
Will the hood still fit over the tank?
Yes, everything fits as it should. Everything looks and fits normal, but that is why its important to do it with tank mounted up. It takes several cycles of heat/ pressurize/ cool/ repeat. to get it to stretch and stay.
A 1/2 gallon (actually about 1/4 cup less than 1/2 gallon) is all I could get without effecting the fit. I think the first area you will start to see any problems in fit would be where the back of the front fender connects to the front of the rear fender. that would be the first spot. the next would be the hood. DO it gradually. You will see the tank expand as you pump it up and it only takes a few lbs of pressure. If it starts to buldge too much for you as you pump it up ..simply bleed off some air. It wont stay buldged until it completly cools down so you have lots and lots of time.
post pics of the final results
Pressure up the tank with air then use a heat gun to enlarge the areas that aren't critical as far as fitment.
You can get at least a gallon depending on how far you want to go.