Clutch plates

[Trigger]

I always run 20/50 high zinc in the summer 

[Pauarc]

What does the high zinc do

[K2-K6]

What does the high zinc do

Zinc "zddp" is only really active when the oil film breaks down due to very high pressure.  It protects against cold weld/spalling in metal to metal contact areas such as cam lobes and followers, also gear teeth faces etc.

Not so relevant to crankshaft, pistons etc.

[McCabe-Thiele (Ted)]

Too much Zinc can clog the engine oil paths in the right concentration it helps protect camshaft parts.

STP contains zinc.

Millers Oils recommends an optimum amount between 1000 – 1400 ppm of ZDDP. Too little won't offer enough anti-wear protection, and too much will not provide increased levels of protection, but can actually create friction and increase wear due to the 'over-plating' of components.

.

[Pauarc]

Can you add zinc to the oil

[McCabe-Thiele (Ted)]

Can you add zinc to the oil

STP would do it in the correct proportion trouble is you do not know the base content before you add it - in reality all good branded oils probably have the right amount as part of the oil specification.

[K2-K6]

Shouldn't be any real need to add anything to a decent spec oil for these engine, theyre not too demanding in the various different aspects of protecting all the components.

By far the most critical is oil condition, specifically dilution by excess fueling from too much choke and short runs. Other than that, you'll be very unlikely to run into any problem.

For assurance, start by finding out what the zddp level is of the oil you've used.

[Pauarc]

Not sure if it has zddp

[K2-K6]

Difficult to find a spec for that oil that says much, either way in respect of zddp presence.

It's definitely a frustrating part of how oil companies promote their product.

Very loosely speaking, any oil used or specified for modern engine that have anything in tbe way of exhaust gas treatment will usually involve lowered content of zinc formulation. This because of longevity in those component with regard to sensitivity to zinc byproduct. They do seem to miss though that a good engine can burn very  very little engine oil, making it's presence in exhaust likely extremely low.

[McCabe-Thiele (Ted)]

Not sure if it has zddp

Most branded modern oils will contain Zinc as a base line ingredient if you go for something like Miller, Manol, Shell, Castrol, Motul, Mobil, Elf, Silcolene, possibly even Comma they all meet the modern specifications even when not fully synthetic.

Or buy cheap Asda Mineral then add STP as per instructions on the can.

[Pauarc]

I have now changed oil to motul 3000 20w50 so much better now

[Trigger]

I have now changed oil to motul 3000 20w50 so much better now

I did advise 20/50 mineral high zinc weeks ago 

[Athame57]

I have now changed oil to motul 3000 20w50 so much better now

That's what I'm putting in my bike tomorrow after I've painted a couple of parts first.

[Pauarc]

Yes trigger should have listened
the putoline 10w40 was no good for my CB750k
Just now I like to get tikover down to about 1000 steady?mainjet 120 slow 40

[Trigger]

I have now changed oil to motul 3000 20w50 so much better now

That's what I'm putting in my bike tomorrow after I've painted a couple of parts first.

No good in a 400 engine. You need to use 10w/40 or 15w/40 mineral oil