19. Header Tank - Sight Gauge

I had my local welding shop weld a couple of bungs on each tank for the sight gauges. There were bungs on the tank from the factory but I wanted a different position for the sight gauge on each tank. For two reasons, first, to locate the sight gauge to a more protected position and second, to make it easier to read from the front seats. The stock position had the sight gauge sticking out toward the middle of the baggage area where anything being tossed into the area could snag the gauge potentially causing a leak. Also, being that I am opting for a second header tank, the second gauge would be on the back side of the tank using the factory bungs and be unreadable. So, it was an easy fix to have a couple of bungs welded in the correct clock position for each tank. This does make a right and left tank though.

Once back from the welder, first order of business was to pressure test the tanks to make sure the welds were leak proof. I inserted a valve stem in to each drain that was already drilled and tapped from the factory. Pumped about 10psi into each tank and used soapy water to spot any leaks. None found.

 

Next step was to drill and tap the two holes in each tank for the fittings required for the sight gauge. Once the holes were drilled, I tapped them with a 1/4x18 NPT pipe tap. I took my time so as not to over tap the hole. Since NPT threads are tapered, you definitely do not want to over tap them. A general rule when tapping NPT threads is to be able to screw the fitting in by hand approximately three revolutions. It's mandatory to tap a little, back it out, try the fitting and repeat. I was able to tap all the holes to this spec.

 

I used a cheap piece of plastic tubing, cut it to the correct length and test fit everything. The final tubing will be fuel proof and clear. There will also be a "fuel floatie" in the tube, a bright orange ball that floats which will help see the fuel level.