10W-50 oil

[anparkinson]

Just serviced my K3 and put 10W-50 fully synthetic in it instead of 10W-40.

Big difference - engine quieter and gear shifts MUCH smoother.

[SteveD CB500K0]

Probably more to do with the synthetic than the grade.

Modern oils are sooo much better...

Does the clutch slip? [be prepared to fight off the oil aroraks...]

 

[Bitsa (Ralph Wright - RIP)]

I am with you Steve read so much about oils Don't really know which way to go.After total rebuild went synthetic no problems now back on good old 20/50 and still no problems.These motors were designed to run on mineral oil as there was no synthetic about then.Oil pressure at the moment on mine is higher than Haynes speck says but I do not know how good the gauge is.The oil light never comes on only when its off.Its bloody hot here and even on tickover it never comes on or flickers so its 50/ 50 for me.In my day we all used duckhams 20/50 green oil went like piss after a good run.What do you all think?
Cheers
Bitsa

[ST1100]

Probably more to do with the synthetic than the grade.

Dunno... recently I'd to 'downgrade' from 5W60 to 5W50 (due unavailability of the first) on my touring rig, and I now sense clutch engaging not as precise...

Will the SOHC's accept full synth without problems (besides mandatory clutch plate cleaning)?

[Bryanj]

Synthetic is just too damn expensive for me and i know for a fact that on the merc big comercials they "Burn" oil using synthetic but don't when on mineral

[ST1100]

I've heard the fully synthetic can cause seepage from oil seals that weren't designed for it, something to do with viscosity I seem to recall.

Seems logical on vintage engines, but what like after a full rebuild, with all gaskets and seals being replaced?

That an engine previously operated on dino oil, will start to 'use' oil for some time after a swap to synth as the deposits will dissolve and it'll take some time till new deposits build/seal seems also plausible.

[SteveD CB500K0]

Ah, but...

[I love oil threads...]

Oil will meet the 10W/40 or 20W/50 spec whether it is mineral or synth (?)

I don't even use synth in my Triumph Tiger as it is far too expensive a luxury when the thing is designed for semi-synth.

[Bitsa (Ralph Wright - RIP)]

I agree silly money
Regards
Bitsa

[LesterPiglet]

I must check what oil I used and report as my bike is now weeping. A friend brought it from his work so I don't know whether it's mineral or what. It has never done this before. It seems to be coming from sump/crank/rocker cover and tappet covers.

[anparkinson]

I have no issues with clutch slip with the synthetic 10w-50 and no oil leaks at all. The bike doesn't burn any oil between its annual changes, normally about 1,500 miles.

[matthewmosse]

I had cluch slip with one particular semi synth oil that was cheap. I now use a 'fleet' oil suitable for petrol or diesel plus turbo engines that seems to be fine with all my Hondas and isn't too expensive. At one stage I had an engine that leaked on evey joint or so it seemed, I assumed atthe time it was due to the age and fact it was a low milage US inport that had been stood a good while but on reflection it was at the time I tried that cheap oil and the leaks did eventually stop which might well concedentally be when I filled with more costly oil. I always run 10/40w and try to not switch brands too often. Silkolene got stupidly exspensive and I've not found a cheap consistently available oil that's sold somewhere convienient for me so I use that Morris 'fleet' oilthat is sold in farmers merchants for quads, handily I can also put it in our landrover or my dumper too. Since it's main target use is farm quads which are aircooled jap bikes with wet clutches I recon it's gonna be formulated closer to the desired speck than a lot of dedicated motorcycle oils that assume moden requirements.

[Bryanj]

If you look into the specs originaly quoted  the Silcolene(Now Fuchs) Trasnfleet 10w40 was exactlty the correct spec for the 70's Hondas and as it's changed every 1500 miles (Or supposedly annualy if you don't go that far) why buy the expensive stuff.

If you can't get that look at the Tesco own brand NON Synthetic DIESEL oil, it also is the right spec and at £12 a can not too bad on price

[ST1100]

...why buy the expensive stuff.

Can the change interval not be extended with full synth oil?
AFAIK do they feature abilities supporting such... besides reduced wear and chemical reactions while use...

[Bryanj]

Can't realy extend the intervals as its used as gearbox oil as well which is what hammers it

[ST1100]

Yes, but don't they have a higher shear resistance?

On my touring rig(s) (gearbox also in the engine oil) we've intervals of 12.000km/7500miles...

Or is the blow-by the issue?