The International CBX Owners Association

Wheather a person uses Amsoil, Mobil1, etc. is this just regular auto oil or is it a 4 stroke oil. Is it ok to run regular auto oil. I thought 4 stroke motor oil is important because of the design of the motor and the high temperatures?
Thanks

In a motorcycle like the CBX with a unit motor design, you should not run automotive spec oil. These have additives and friction inhibitors that will adversely affect the performance and function of your engine components, e.g.: the clutch and the transmission. Some do anyway and report they have experienced no problems. I do not. I run a motorcycle specific 20W50 in most my of bikes, a special synthetic in my Ducati and automotive oils (Mobil 1) in my BMWs. Their powertrain is designed like a car's with a separate motor and transmission and a dry clutch between.

Amsoil is synthetic and specific for four stroke motorcycle engines. My trial with Mobil 1 showed a marked increase in oil consumption.

Most times the volatility of a oil is directly related to the base stock quality. The disparity between the Amsoil and the Mobil synthetic oils is likely a result of the specific PAO base being used.

Most companies will use a PAO4 fluid for 0W and 5W properties due to the acceptable performance with regard to cost. Higher quality lubes will use a PAO6 fluid for a base in their 5W and 10W fluids because of the stability of this fluid. It's costlier to do this but often times a certain OEM specification will dictate its use.

If you're ever given the choice of choosing between a PAO4 or a PAO6 base fluid, choose the PAO6. It's more expensive but you'll see the benefits years down the road.

When heat is a issue, such as with a air-cooled, in-line 6 cylinder motorcycle (I don't know who'd make one of those crazy things), the use of a Ester based fluid might be necessary if you live in a hot climate. Redline, Motul, Torco, Elf/Total/Fina, etc, make ester fluids but they're expensive and not necessary for most applications.

It's likely that the consumption difference between the Amsoil and the Mobil was because of the PAO base used. If you notice these obvious differences I'd suggest sticking with the fluid that is less volatile even if it means paying a bit more.

Another issue to consider when choosing between automotive oils and motorcycle oils is the addition of viscosity index improvers *viscosity modifiers. Not meaning to rattle but this is important stuff. The following are all modifiers. You'll notice that their names are indicative of plastic. This is exactly what they are; olefin copolymers (ocp's), hydrogenated styrene-diene copolymers, styrene esters, polymetharylates (pma's), mixed alkyl methacrylate-vinyl-pyrrolidines, aminated ethylene propylene, mixed alkylmetharcrylate ethylene/propylenes - all reduce the oil's viscosity change with temperature. They increase the viscosity of the base oil as temperature rises when the base oil it trying to thin. You want as few of these things in your oil as possible. The way you stay away from them is by using a more stable base fluid.

This data isn't really available to the general consumer but if you write to the oil companies and befriend their research chemists you can usually find out a great deal of information.

OH, I almost forgot why I posted to this thread. Mobil's motorcycle oil uses a much higher quality base fluid than does their automotive oil for the above mentioned reasons. Unfortunately it's very expensive.

Sorry to ramble,, it's 1 am and my brain aches now. Good night guys!!!

Not a ramble FowVay but an education....

Here is a video link showing Dave McMunn taking the cylinder off the Dawgie at the 100k mileage mark...more/less. (Owner ran bike with broken speedo cable for 5 years or so true mileage is unknown)

Check piston condition!

http://www.youtube.com/watch?v=O_u-D4vfUjw&NR=1

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

I switched over to Mobil 1 15/45 or 15/50 (forget what is the right weight) car oil in mid 80s or so.......when it became available so maybe 2/3rds of the 100k miles was using it.

At this time my X smoked on deacceleration sometimes and a bit less on acceleration, but this went away with the Mobil 1. Shifting was alot better and noise was cut down a bit. I did get some weeping at the valve cover gasket and a few other places.

Sooooo....as far as what oil to use in an X.............I recommend you use what you want/feel good about after studying the matter, reading great info like FowVay presented ...or just go with with what others here have used with success and recommend in CBXs ...... after all if oil is a major concern and caused motorcycle engine failures most of us would be seeing hundreds broke down along the road each year........wouldnt we.

If you try one brand of oil and for some reason do not like it........go to another the next oil change.

Mike