Fork and Engine oil

[sam_vfr]

What the title says, what fork and engine oil would people recommend for a CB550 K3?

If it makes any difference for the fork oil, I weigh around 80kg's

Just looking for some feedback as I've read a lot of different things!

Thanks

Sam

[Bryanj]

Tesco diesel MINERAL 10w40 for the engine and 30 weight fork oil

[totty]

I'd go lighter on the fork oil, I found 30 over damped and dropped to 20. Although I've seen a website that showed how much it differed by brand so there is a bit of pot luck in it.

[Bryanj]

Sorry not good with these new fangled metricated  numbers just worked out that that is a lot lighter than me so yes 20 weight, one i use most is i think Rock oil

[deltarider]

Recently I changed fork oil from 10W to 7,5W (Shell Advance) which is about ATF weight. ATF was what Honda prescribed back then. By comparing partsnumbers I discovered that my model CB500 has in fact the same fork legs as the CB550K2, so instead of 160 cc I filled them with 145 cc.
As long as you don't operate your motor around zero degrees, 15W-40 is maybe a better choice than the all temperature 10W-40. Honda France prescribed even 20W-40.

[TonUp]

I changed the fork oil on my CB550F2 to 5w30 engine oil - the forks are much better and work very well.

[flatfour]

I just use ATF for the forks, as we did in the 1970's and Putoline DX4 10w/40 for the engines in winter and the same brand but 20w/50 for the summer.