Engine oil Q's

I'm well aware that oil topics are more than common, at least on forums for "modern" bikes. I am about to get one (maybe two) KZ (1978 and 1984) and I am wondering what oil to use in those engines. So, sorry if my questions are irritating for some here...

Back in the days I was riding my KZ1100, I was using kind of standard, off the shelf, engine oil (Castrol as an example). But for my current bikes, I am using either Shell Rotella T6 or Motul 5100. Because I assume those oils are not really compatible with those old air cooled engines, which one(s) should I use?

I know there are SAE and JASO ratings to consider but, to make it short, are there some easier recommendations? I mean, something like "Castrol GTX" or "Amsoil XYZ"?

Thanks!

Rotella is good. T4 or T6 are both excellent.

Nessism wrote: Rotella is good. T4 or T6 are both excellent.

Really? Even for those old air cooled engines?
That's great then as I already have a few jugs here.
Thanks!

Everybody has different opinions on oil. But really, any modern oil will be far better than what was on offer 40 years ago.

There is one exceptions to that rule - friction modifiers.. These older engines with wet clutches want no friction modifiers as they do bad things to wet clutches. Looks for the JASO-MA specification on the bottle, if the oil is JASO-MA compliant, it will be fine to use with wet clutches, no friction modifiers.

Anti-wear additives are also important as they are included to reduce start-up wear on engines - you do want these. You might have heard of the zinc and phosphorous content of oil and how modern oils don't have as much as they used to due to emissions. This is true, but there's a little more to it. The zinc and phosphorous compounds (ZDDP and ZDTP) are bad for catalytic converters and so are not common in most oils. But they used to be included to combat lead oxides in oil - a problem we don't have any more. They can also increase carbon deposits on the valvetrain which is undesirable.

Oil technology has come a long way, so even though ZDDP/ZDTP are still effective anti-wear additives, they have been all but replaced by other additives that do as-good or better (Boron and PTFE are good examples), and don't have issues with emissions.

In the end, you need a JASO-MA oil of the correct grade. Get a good brand (Rotella is good by all accounts), and you'll be sweet.

Yes Irish yobbo is spot on here, I used to think that 10w 40 was 10w 40, just buy a good brand and your fine, not so! When I first bought my z1000 I changed the oil straight away with a modern silkolene 10/40 and I had bad clutch slip, I saw a local kawasaki specialist of some 47 years who I soon became good friends with and he said get that stuff out! You want Rock oil gamma, that's made especially for these bike's and as he was retired he let me know of two placea near to me that sell it. So that's what I use and it's honestly perfect, I pay £19.50 for 4 litres, the only thing I'm not sure of is if it's common oil in the u.s or not? ......

Rotella T4 and T6 are JASO MA rated. T5 is not.

T4 or T6 Rotella it will be then. Thanks for the info guys!

Irish Yobbo wrote: Everybody has different opinions on oil. But really, any modern oil will be far better than what was on offer 40 years ago.

There is one exceptions to that rule - friction modifiers.. These older engines with wet clutches want no friction modifiers as they do bad things to wet clutches. Looks for the JASO-MA specification on the bottle, if the oil is JASO-MA compliant, it will be fine to use with wet clutches, no friction modifiers.

Anti-wear additives are also important as they are included to reduce start-up wear on engines - you do want these. You might have heard of the zinc and phosphorous content of oil and how modern oils don't have as much as they used to due to emissions. This is true, but there's a little more to it. The zinc and phosphorous compounds (ZDDP and ZDTP) are bad for catalytic converters and so are not common in most oils. But they used to be included to combat lead oxides in oil - a problem we don't have any more. They can also increase carbon deposits on the valvetrain which is undesirable.

Oil technology has come a long way, so even though ZDDP/ZDTP are still effective anti-wear additives, they have been all but replaced by other additives that do as-good or better (Boron and PTFE are good examples), and don't have issues with emissions.

In the end, you need a JASO-MA oil of the correct grade. Get a good brand (Rotella is good by all accounts), and you'll be sweet.

I'm unaware of any automotive/motorcycle oil on the market that doesn't have zinc and phosphorus in it. Current levels are about 1100-1200 ppm for diesel oils like Rotella and about 700-800 for auto oils. Motorcycle specific oils tend to fall between these two levels. Back in the KZ era the levels were higher, I'm not positive how high but about 1500 is what I suspect. Modern oils have other additives to offset the Z&P levels so all is not lost though.

As has been discussed here many times, MA certified oils are a good hedge against damaging a wet clutch. Personally though, I'll run just about any diesel oil in my bikes regardless of the MA cert. Most diesel engine oil manufacturers don't want to spend the money to get the cert because the bike market is very small overall, however the oils are perfectly fine for use in bikes. Shell seems to be one of the only companies catering to the bike crowd with their Rotella MA cert, and for that they deserve our support so choose with confidence.

I find this to be a continuously interesting topic, and I am always pleased at how civilized the conversation on KZR is when this comes up. One thing at keeps me interested is that we have here a moving target as oil companies continue to develop their products to meet a very complicated set of parameters.
When it comes to these old engines, I wonder if there comes a point of diminishing return? Several years ago, MCN (the U.S. one) conducted a pretty extensive test of motorcycle specific engine oils. As I recall, Mobil 1 4T killed the competition in every category, save price. Well it should as it is a very expensive oil. What I wonder is this, in an engine designed long before such lubricants were widely available, does Mobil 1 actually provide enough measurable, real world additional protection over something like Rotella T6 to justify the extra expense? Evidently I think not, as I run Rotella even in my much newer ZRX.
As mentioned above, even rather pedestrian oils today provide more protection than the premium oils of old.
Although not specifically mentioned in this thread, I think it is still important to stay within Kawasaki's recommended viscosity range.

TexasKZ wrote: I find this to be a continuously interesting topic, and I am always pleased at how civilized the conversation on KZR is when this comes up. One thing at keeps me interested is that we have here a moving target as oil companies continue to develop their products to meet a very complicated set of parameters.
When it comes to these old engines, I wonder if there comes a point of diminishing return? Several years ago, MCN (the U.S. one) conducted a pretty extensive test of motorcycle specific engine oils. As I recall, Mobil 1 4T killed the competition in every category, save price. Well it should as it is a very expensive oil. What I wonder is this, in an engine designed long before such lubricants were widely available, does Mobil 1 actually provide enough measurable, real world additional protection over something like Rotella T6 to justify the extra expense? Evidently I think not, as I run Rotella even in my much newer ZRX.
As mentioned above, even rather pedestrian oils today provide more protection than the premium oils of old.
Although not specifically mentioned in this thread, I think it is still important to stay within Kawasaki's recommended viscosity range.

If you have a little time to [strike]waste[/strike] read through this guys blog... 540ratblog.wordpress.com/2013/06/20/moto...l-wear-test-ranking/

He's opinionated as all get out, and no doubt one of those guys that throws gasoline on oil debates, but I think he makes a lot of good points. I bought some car oil based on his recommendations. Good fun.

Looks like it’s common agreement around JASO-MA, but what about mineral? Semi Synthetic? Synthetic?

When my KZ650 was new (1977) I used Castrol GTX motor oil. It worked fine. Over time though Castrol changed the oil formula and the new formula destroyed or helped destroy the bike’s clutch. In 2006 I learned about ZDDP, cars’ catalytic converters, and JASO-MA standards. I replaced the bike’s clutch parts and I switched to Mobil-1 4T motor oil. That is very good oil, but over a couple oil changes I found my starter clutch began slipping when I started the bike. Once the slipping got really bad I bought but did not install all new parts for the starter clutch. As a test before attempting to install the new parts I began using Shell Rotella 6 motor oil. It is JASO-MA compliant. My starter clutch stopped slipping and I have not installed any of the new parts. I have been using Shell Rotella 6 oil for more than 3 years with zero problems, so for now I plan to keep using it. I learned about Shell Rotella from this web site – thanks! Ed