Normally, you wouldn't want to clutter up the look of your new custom chopper with instrumentation--of any kind. You certainly don't need a tach, because with a big V-Twin it's fairly easy to gauge the revs by ear, unlike a multi-cylindered sportbike where 8,000 rpm may as well be 14,000. A speedometer can be useful, especially to those of us who live in areas with high concentrations of law enforcement personnel--but then you're back to boogering up the look of your clean bike again.
If there ever were a gauge that you could deem a necessity, it would probably have to be an oil pressure gauge. Harley's typically don't have a lot of oil pressure and when you ride the desert highways in the southwest during the summer in 115-degree-plus weather, oil pressure can become almost non-existent. Things get worse if you're lucky enough to get caught in the inner city during rush hour, with thousands of cars all around you and nowhere to go. It's in conditions such as these that we've seen even the latest-model Harleys display oil pressure in the single-digit range. Whether it's lost pressure from extreme heat, a busted oil line or oil cooler, an oil pressure gauge can give you ample warning and save your expensive engine from certain disaster.
Since one of our springers is regularly ridden in the hostile environment described above, we thought it would be a good idea to ring up Arlen Ness to order one of their trick rocker box mounted oil pressure gauge kits.
01: The 5.2-gallon gas tanks...
01: The 5.2-gallon gas tanks on this particular softail made it impossible to access the rear rocker cover bolts without unbolting the tank. Once the three tank bolts were removed, we were able to get an Allen wrench on these two right-side rocker box bolts to remove them.
02: The next thing we do is...
02:The next thing we do is to coat the threads of the gauge where it will attach to supplied braided steel hose with a Teflon thread sealant, like this PST from Permatex. We prefer the liquid sealant in a tube over Teflon tape since tape can flake off and travel through the oiling system.
03 After attaching the braided...
03After attaching the braided hose and sliding it through the gauge mounting cup,our gauge is then installed in the billet rocker box mount, turned to the desired position and the set screw is tightened to keep the gauge from rotating in the mount.
04: To install the gauge,...
04: To install the gauge, use the supplied bolts to bolt it to the rocker box. Don't forget to replace the gaskets that go underneath the gauge with the new ones that come with the kit to prevent any possible leakage.
05: The next thing we do is...
05:The next thing we do is to remove the plug covering the tappet screen. This is where the fitting to tap into the system will go.
06: Don't forget to clean...
06:Don't forget to clean and inspect the little screen while you have access to it. Clean it with a good solvent or air pressure and make sure it isn't clogged by any debris and there are no signs of holes in the screen. There is a spring that slides over the screen that is not shown in this shot. Don't forget to replace the spring before screwing on the fitting.
07: Since the Ness fitting...
07:Since the Ness fitting has an O-ring like the stock Harley plug you can screw it in without adding any thread sealant.
08: After coating the male...
08:After coating the male end of the 1/8-pipe fitting in the kit, it can be screwed into the top of the Ness tappet plug adapter. The last step is as easy as attaching the lower fitting on the braided hose to the 1/8-pipe fitting with a 1/2-inch open end or flare wrench if you have one.
09: Due to our over-sized...
09:Due to our over-sized fuel tanks, we had to re-adjust the position of the gauge face for viewing from the rider's seat, but it looks fantastic and works great!