Honda CB350 / CB360 / CB450 CB350 How to Access and Clean the Oil Filter

Posted by Brenden on 4/25/2018 to CB350 / CL350 / SL350
Oil changes are regular service on any engine, however most vehicles (cars and motorcycles) use a replaceable oil filter that is changed out with the oil. The twin cylinder Honda motorcycles from the mid 70's (Honda CB350, CB360 and CB450 families of bikes) use a different type of oil filter system than many are familiar with; these engines use a centrifugal style oil filtering system. This service process applies to the following Honda motorcycles listed on the chart below:

The Centrifugal Oil Filter System is Found on the Following Honda Motorcycles

The centrifugal oil filter system works by pumping oil into a metal cup or "rotor" which is spins at engine RPM. As the rotor spins at high speed, any dirt or debris in the oil is pressed to the inside of the rotor and separated from the oil, which is then pumped back out of the rotor and through the engine. The system works similar to your washing machine on the spin cycle. The oil rotor should be opened cleaned out every other oil change (3000 miles / 5000km), which depending on model will require some minor dissembling of the engine. The oil pick up screen should be cleaned of any debris as well while the side cover is removed; engines like the CB360 are easy to remove the screen, but CB450's are more complex and it is often easier to clean the screen while it is still in the bike. If the bike is new to you, we suggest performing a full clean and inspection of the oil rotor, pick-up screen as well as all the components found in the right side of the engine crankcase.

 When servicing the oil rotor the right side of the engine case needs to be removed to access all the parts for cleaning. The factory JIS Philips screws need to come out; an impact driver makes this job a snap and is a needed tool to keep in your toolbox when servicing your vintage Honda CL / SL / CB350; CL  / CJ / CB360 or CL / CB450 and CB500T. We supply both a basic "oil change" gasket kit as well as a more comprehensive "service gasket kit" which contain all needed gaskets and O-rings to complete the oil filter cleaning.

Both the oil drain plugs and the side cover screws tend to get chewed up after years of abuse. Stainless Allen bolt kits are available as replacements for the side cover screws, which makes removing the covers in the future much easier. We now manufacture our own high quality drain plugs in the U.S.A., in standard style and premium version called the "Black Hole." 

A quick tip for future engine servicing: When installing the side cover gasket, apply a light coat of grease to the outer perimeter of the gasket surface. This will keep the gasket from sticking in place when removing the side cover in the future. Often you can re-use the gaskets a few times before they need to be replaced, assuming they do not rip or tear. Applying anti-seize compound to the Allen screws will ensure easy future removal.

The following video outlines the oil filter cleaning process in detail as well as the variations you may encounter between the models.

Parts & Tools needed to perform oil filter clean per bike family:

Impact Driver (A toolbox must!)

CB350 (CL350 & SL350*)

*SL350 K1 & K2 use a different side cover gasket & stator cover gasket from the CB, CL, SL350 K0 engines, select the proper option for your sub model.

CB360 (CL360 & CJ360)

CB450 (CL450 & CB500T)

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