Multi-weight oil?

 

Thanks for the advice last week on tire sizes and bike covers.  The
tire webpages were quite helpful, and I don't plan to use the bike
cover except at home also.

Here's another even more? elementary question.

The owners manual for the Honda CB 450, made in 1969, says to use SAE
30 over 59 degrees F, and SAE 20 or 20W from 32 to 59^ F.  (SAE 10
below 32 but I won't ride then, I don't think)

Don't they have an oil by now that I can use for both temperature
ranges?  10W-30?    Is there a 20W-30?

Is it a bad idea to use a multiweight oil in a bike this old, because
it is a detergent oil and straight 20 or 30 is not?  The bike is 37
years old, but only has 2,800 miles on it.   So why would a detergent
oil be bad for it?

Do manufacturers recommend multi-weight oil in newer bikes?



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BTW, how do I know if I have a wet clutch in my Honda CB 450 from
1969?

A lot of the old articles on engine oil make a distinction regarding
wet clutches.



wrote:


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mm wrote:

 10w 40 is good unless you are riding it in the city when it's 80+
degrees then use 15w40 or 20w 50.

 Yes the Honda has a "wet clutch".

 



Yeah, and yeah. I've seen every combination of { 10W | 20W } X { -30 |
-40 | -50 } :-)


A detergent oil is probably better for it.


Yes, they do. BMW, for instance, recommends 10W-40 for their
water-cooled bikes and 20W-50 for their oil-cooled bikes.

It took the general aviation industry a long time to approve multiweight
oils for little Cessnas and stuff, but after one particularly cold
winter when people gut fed up with having to go out and start their
engines on a regular basis just so that they cold go on doing that, the
FAA looked into the matter. They researched multiweight oils and
subjected them to the kinds of tests you'd want the FAA to to and
discovered that they work as advertised and do not pose any additional
hazard to aviation piston engines. You can probably get away with
putting multiweight oil in your bike.

--
Timberwoof <me at timberwoof dot com>
faq:  http://www.timberwoof.com/motorcycle/faq.shtml

 



IIRC, my '75 Yamaha TX500, a dohc twin somewhat similar to your CB450,
called for 10w40 or 20w50 depending on season.  Since you aren't planning to
ride below 32o, I'd opt for the 20w50.


Tom K.