How much is too much? Oil consumption question.

[Buber]

Hi all!

I just went tinkering with the oil (change was due), filled in with european version of semisynth Rotella T and will report eventual changes. But.... I noticed that drained oil was really below what i should have got out of the engine.

Hence the question - how much oil consumption there should be? Of course in the ideal world it should be none, but we are living in the real one
I would appreciate any experiences you guys have had. And quantities per kms or miles

Thanx a lot in advance!

[Ibsen]

I believe my 650 is consuming approx 3.0~3,5dl each 1000km. And it has been like this since I bought it 3 years ago.
I read somwhere that some factories have calculated that an oil consume of 1litre pr. 1000ccm pr.1000 km are acceptable. That would be 6.5dl each 1000km for the 650.
A friend of mine who happens to be a bike mechanic have got a 1979 Kawasaki Z1000 MK II. His bike consumes approx the same as my 650 and he say it's normal for both bikes.
I do suspect that I should have replaced the valve stem seals and that might reduce the consume a little, but as long as the bike runs good and don't smoke badly, I haven't bothered to take the cylinder head off.
This spring I filled the engine with Castrol GPS 10W-40 synthetic based oil btw. And the consume seems to be the same as with the 10W-40 Quaker State mineral mc oil I have used the previous seasons.

[Volker_P]

Rather than oil consumtion one should worry about the oil level in the engine. Finding out it consumes oil by the amount coming out after a change is a dangerous strategy that will kill the engine sooner or later.
I would guess a good CB650 engine should take at most 0.2l/1000km. At least that was my beginning value some years ago but it already had a scratch in one cylinder at that time causing some smoking at higher rpm. Meanwhile it consumes about 1l/1000km when ridden softly, however it has above 100000km now. The oil consumtion increased smoothly so I see no reason to worry. It just reflects the wear of the cylinders and rings. It starts smoking visibly above 6000rpm.
A reason to worry is when oil consumtion increases from one day to the other, which could mean a broken ring or valve shaft seal.
Sometimes the oil consumtions starts to increase also when one changes to synthetic oil at an engine that already ran some 10000 miles with mineral oil.
So I guess it is rather these things than the pure amount of oil. But 5l/1000km would be too much anyway.
Btw: although it can pour oil around everywhere, the head oil leak does not contribute very much to oil consumption.

[Ibsen]

I agree with you Volker. I check the oil level every 300~350 kilometres and I normally refill with 1.5dl each time to keep the oil level high all the time.

[Buber]

Thanks guys!

I was not able to reply sooner, as it is holiday season, so I was away a bit with the kids.
Thanks for the info. It sems that all is well, and yes, level was a bit low, but still acceptable, and i was going to change it anyway.
So now I'm loaded with Rotella - in Europe it sells with a funny name - Rimula. The main reason (for me) was that those oils are quite cheaper per liter than motorcycle equivalents (semi-synht, or full synth), and since now I'm taking care of my bike and 2 Viragos, I wil buy a 20l drum , and that will save me a penny. And guys on sohc4 forum are quite enthusiastic about it, so why not? So far the gearbox is working better for sure, but I want to ride some more for more impressions. Before I had mineral 20w50.

And finally weather improves.

P.S. - Ibsen! I just went (working) on a cruise through fjords and to the nordkap. I will be back in the fjords on the bike for sure! (I will skip nordkap, I think its overestimated) But your petrol price.... and you are sitting on oil!!!!

[Ibsen]

Yes, the petrol prices are really steep although we produce the oil ourself.
I have never been to Norkapp myslef, and it isn't on my "10 things to visit" list either.

Oils for diesle engines will in general work well in a motorcycle engine. At least they have till now.
Btw, did you know that Shell changed their formula for the Rotella, at least in USA.
Rotella T is no longer high in Zinc content. They have adapted their oils to the new heavy diesel engine specifications, the API CJ-4 Specification.
If you want to play safe there are two specs you should look for on the bottle:

JASO MA (no friction modifiers)
API SG

[Volker_P]

Do not worry about oil quality because we have a 1980's engine based on 1970's (or earlier?) constructions and every oil today is much better than the engine was designed for. Today's motorcycle oils have to work in 600ccm 100hp engines, no need for that. As airheads tend to get a bit hotter one may have some doubt on really cheap supermarket oil (even if API-code is sufficient or much more) as additives of cheap oils are usually less stable against temperature. I think every non-discount priced mineral oil will do the job perfectly. One may also use a really cheap one and change more frequently.