Full or semi-synthetic for an old CB-1?

peckerhead

Hi lads and lasses,

Nothing like the summer to bring out all the engine oil posts... - so here's a quick yea or nay one for you.

Looking to change the oil and filter in an old (1989) CB-1 400. I see a lot of "service packs" on eBay for 4l Motul 5000 10W40 semi-synthetic plus the required filter. But then a mate whose opinion I'd normally trust says no, that's a very high-revving engine (true) with a wet clutch (also true) and that I'd be better off paying for full synthetic (about €50 for 4l). *Especially* as it's an old bike (about 55k on the clock).

Ridiculous overkill, or words of wisdom?

CJhaughey

peckerhead wrote: »

Hi lads and lasses,

Nothing like the summer to bring out all the engine oil posts... - so here's a quick yea or nay one for you.

Looking to change the oil and filter in an old (1989) CB-1 400. I see a lot of "service packs" on eBay for 4l Motul 5000 10W40 semi-synthetic plus the required filter. But then a mate whose opinion I'd normally trust says no, that's a very high-revving engine (true) with a wet clutch (also true) and that I'd be better off paying for full synthetic (about €50 for 4l). *Especially* as it's an old bike (about 55k on the clock).

Ridiculous overkill, or words of wisdom?

I run Motul 5100 in bike of similar vintage.
Semi-synth is fine is a bike of that vintage, no need for full synthetic.
Modern oils are very good compared to the stuff that would have been in existence back when the bike was new.

corkgsxr

Semi is perfectly fine

peckerhead

Cheers, kinda confirmed my own thinking... (was full synthetic even available back then?). I'll throw in the semi- and keep an eye on the temperature gauge - in fairness it never even reaches the midway point no matter how hard I push it. Out on it yesterday for the first time in a good while and had forgotten what a nippy little yoke it is; looking forward to blowing away a few cobwebs over the next few weeks...

CJhaughey

peckerhead wrote: »

Cheers, kinda confirmed my own thinking... (was full synthetic even available back then?). I'll throw in the semi- and keep an eye on the temperature gauge - in fairness it never even reaches the midway point no matter how hard I push it. Out on it yesterday for the first time in a good while and had forgotten what a nippy little yoke it is; looking forward to blowing away a few cobwebs over the next few weeks...

Using semi-syn will not make your engine run any hotter than full syn.

Bikerguy

5100 all the way. No doubs about it

professore

Those yokes are bulletproof. As long as there is no "friction reducing" additive in it you should be grand - otherwise the clutch might slip. Just change the oil regularly.