Harley Style Tanks
Our Harley style oil tanks use internal oil lines to vent the crank case into the tank, and to return the oil away from the suction side. The internal vent oil line stands above the full oil level to make sure it vents properly and doesn't syphon back to the engine. The return line is bent down to return the oil back into the tank oil to reduce foaming. Sometimes the fittings are located towards the top and internal lines are not needed.
Triumph Style Tanks
Triumph requires a restricted return line to force oil to the rocker boxes. This is done by closing off the internal return line and drilling a 3/32" hole in the line above the full oil level. This will create the back pressure needed to force oil to the rocker boxes from the tee on the tank return fitting. Also there needs to be a vent on the top of the tank to allow the oil to flow in and out of the tank. This vent is sometimes used as a vapor mist oiler for the chain.
Honda Style Tanks
Honda uses larger oil lines so we offer oil tanks with 1/4" npt fittings which helps with the oil flow. Another necessity is that the return oil needs to be dumped on top of the tank oil to prevent the oil from syphoning back to the motor causing a wet sump problem. We also offer an adapter plate for the motor that makes the line hook up easier by converting the old style lines to npt fittings.
Sample Oil flow diagrams
These diagrams are examples only. Yours may differ for your model
of bike please reference your service manual to make sure that you
plumb it correctly. Just click on the picture to enlarge for better viewing.
We try to make sure the inside of our tanks are clean and rust free. You should always rinse a new tank out to remove any weld scale or dirt that we couldn't get out to prevent any damage to your motor. All of our tanks are pressure checked under water which allows us to find even the smallest leak and repair it before we ship the tank out. Also be careful with further grinding or sanding as to not cause leaks after you get the tank. I hope this page is helpful in selecting the right tank and assures the end user that they are getting quality as well as service.