Topic: Best Oil for 74 CB750

[PeWe]

Important issue to discuss since oils have changed since the 80's. There are also different oils available depending on where you live.

If you want a motorcycle oil with some zinc... Yes, I flag for this oil again as in 10 other threads    I should get bonus from Red Line oil company!   

Many other motorcycle oils have around 1000-1300 ppm.

This oil cost some extra but can withstand longer oil change intervals. 8000 km is most likely no problem. I have not come to this oil yet since I test other since break-in of new pistons. I have over 20 bottles 20W-50 in my garage 

It take some oil changes to fully get the new oil in since almost 1 L will stay in, 2,5 L drained out. This means 2.5L new oil, to mix with the other 1L.

I'll see if my clutch will complain now with bigger bore and much more torque. It was OK with 836 and 80rwhp.
It should be OK
Blended with specific friction modifiers that are compatible with wet-clutches, suitable for JASO MA applications

https://www.redlineoil.com/product.aspx?pid=110&pcid=21

API Service Class   SJ/SG/SH JASO MA
SAE Viscosity Grade (Motor Oil)   20W50
Vis @ 100°C, cSt   20.1
Vis @ 40°C, cSt   141
Viscosity Index   165
CCS Viscosity, Poise, @ °C   50@ -15
Pour Point, °C   -45
Pour Point, °F   -49
Zinc, avg PPM   2125
Phosphorus, avg PPM   2100
Molybdenum, avg PPM   425
NOACK Evaporation Loss,1hr @ 482°F (250°C), %   5
% Viscosity Loss, 30 Pass ASTM D6278   0
HTHS Vis, cP @150°C, ASTM D4741    6.1

[Duke McDukiedook]

As has been discussed ad nauseam Spectro is another good choice if you need Zn in your oil.

[grcamna2]

Does Redline make any M/C oil that is not synthetic,like 10/40 or 20/50 ?

[Doo Bee]

European Formula is 1000 PPM Zinc. Modern oils use GTL technology and claim to be extremely anti
wear and don't need zinc. Read 540 rats blog and google it. I am old school and will still break in my
SBC flat tappet cams with Valvoline mineral racing oil, cam lube on lobes, 1/2 a bottle break in juice.
My Honda's get cam lube lobes and Valvoline mineral racing oil. I just switched last year to the latest
Mobil 1 and it shifts great. Time will tell--- I have a cycle-x #3 cam in with a pretty high lift!!! I am
not rich and don't want to chance breaking in a new cam with a synthetic. I think you need the zinc
to burnish the lobes with a fast idle when new!! You have to drain the break in oil anyways to get
contaminates out!