oil

[steven400/4]

what type of oil should i be putting in my cb400/4???

[hairygit]

According to the Honda manual, for U.K. use it should be "Premium quality 10W40"

[ST1100]

it should be "Premium quality 10W40"

And how does such translate into todays world?
Will a modern full synth* be OK, or might such harm bearing alloys, gaskets and seals?
What if one uses higher/wider specs like 5W50 or 0W60?

* besides the risk of dissolving existing coal buildups, thus leading to increased oil consumption on the first few thousand miles/kilometers

[steven400/4]

the engine is like new inside it has had a complete rebuild full nut bolt everythink will that make a diff???
steve

[hairygit]

Don't waste your hard earned cash on fully synthetic, there are no real advantages to it, and regardless of oil manufacturers claims, change it at least  every 2,000 miles, and I have seen threads in other areas of this forum suggesting NOT to use fully synthetic oils as they can be detrimental to the engine. It was designed to run on mineral oil, so that is the best to use. As regards different grades 5W50 or 0W60, unless your area has exceptionally cold weather for much of the year (-15c or lower) you are wasting your money, and 0W60 can allow clutch slip when hot!

[SteveD CB500K0]

Oil threads are great!

If members = n, then opinions = (n+1)  

My four-penneth...

In the 70's, only mineral oil was available, so that was what they used.
You can use the modern equivalent (made by Rock Oil or Silkolene) or go for a standard semi-synth 10W-40 (I use Halfords...)

I believe that full synth may affect your wet clutch operation although I've no first hand experience and it may be an urban myth  

Steve

[ST1100]

If members = n, then opinions = (n+1)  

LOL! 

I believe that full synth may affect your wet clutch operation although I've no first hand experience and it may be an urban myth

Methinks the later  (using mentioned under sometimes harsh conditions in my touring rig since >200.000km...)
It however is an MC specific engine oil with friction additives for the clutch and increased shear resistance for the gear box.

Wouldn't dare to pour car oil into our precious ones... 

But here its about old engines, old school designs, different sintered alloys used for bearings/bushings...
What's the true deal there?

[hairygit]

True deal? Stick with mineral oil, change it regularly, and the filter. 172,000 miles on my "winter" CB750F1, Tore the motor down a month ago to replace the camchain, no visible wear on the main bearings, cam towers or rockers, it gets ridden hard, is often thrashed mercilessly, and has NEVER broken down on me. It has the oil changed along with the filter every 2,000 miles

[K2-K6]

It's very hard to argue with keeping the oil in good condition and that would seem to be the the biggest influence in how it protects the engine whichever is your personal choice.

I think most of the decent quality oils available would be quite hard to tell much difference between to be honest if they are used within their operating range.

The engine tolerancing was origninally specified to run on 10w-40, so it would be sensible to start with that as base point unless any specific requirements have a higher priority.

It's very rare to see significant wear on most engine components with oil in good condition. There is always a contributing factor in my experience, like condition/dilution/quantity to promote failure.

[matthewmosse]

I use Morris semi synthetic 10/40 fleet oil, I found comma semi synthetic sometimes led to cluch slip which was a shame as it was