Oil for my motorcycle

I have a 1994 Yamaha Seca II. It’s used oil ever since it was new (about 4oz. every few hundred miles). I always use Yamalube 4-cycle 20W-40 oil. I used to have a car that burned a lot of oil, so I have about six quarts of 10W-40 laying around.

Is it okay to use “car” oil in my bike? Or do I have to use “motorcycle” oil?

Automotive motor oil can be used in a motorcycle if you have a seperate sump for the engine and transmision. If your bike uses the same oil to lube both the engine and the tranny, stick with Motorcycle oil. Somewhere in the back issues of “Cycle” you would find a very good monograph on this subject. Oil is a lot more complicated then people think.

Hmmm, it may be enitrely possible that Booker is right but I haven’t heard of that.

I always use 10W40 Auto oil in my bike, never a problem.

Read your manual- it’ll tell you what standards & viscosity your bike engine requires.

If not, call the dealership & ask. They’ll know if anyone would.

Car oil isn’t going to kill the bike engine, but it might do some damage to the transmission. MC oils are not as slick so that the transmission doesn’t slip. I’d stick with the MC oil. maybe it’s better to just have it check out too.

Oh and Motorcycle Consumer News did a three piece article a few months ago. the web site is: http://www.mcnews.com

One thing you must not do is put in friction modifiers such as Slick 50 or other teflon additives.

The Seca has a wet clutch (in the UK it is called the Diversion)

You’d be as well using car engine oil as long as you change it fairly frequently, say from 2000 to 4000 miles.

In fact using the high performance fully synthetic oils on such a machine is not only a waste of cash but actually not as effective since these are designed for the close tolerance, high revving, high compression superbikes.