Adjusting oil Supply

[tz375]

Allan,
Stop obfuscating. Oil saturation and pre-mix ratio effects on jetting etc, are all interesting ideas but not really pertinent to the issue of this discussion.

The question here is whether the rising rate that Suzuki designed for the GT still appropriate for modern oils in modern riding conditions. You and Eric say "yes" it's better to back off the pump for street conditions and I say "don't mess with it". How much better is modern oil? Well that depends on the oil. How much different is one person's riding compared to the original design. Only they can guess.

We all agree that from half throttle or thereabouts to the top end makes no difference. The pump will be wide open anyway. The only subject of discussion relates to slow speed/low throttle opening riding. Is less more or is more more? You believe less is better and I wouldn't mess with it. Those are opinions, and they differ, and I can live with agreeing to disagree.

Bottom line is that ridden quietly when it's not too hot and the bike is set up correctly, it can run without oil for a remarkably long time before it breaks. If i did most of my riding sedately/responsibly and I used great oil, I might be tempted to tweak the settings, but I don't, so I won't. Your mileage may vary.

[Suzsmokeyallan]

Richard, we are discussing ALL oil pump and premix related issues here and not just one thing.
Ok I'll forgive you for being stubborn and totally set in your ways.

[tz375]

Actually the question from Bill was
"GT380 1971.
Read a lot about reducing the oil supply from the pump when using a modern oil in these forums, which makes sense to me.
But looked though my manual and can’t find anything on adjusting the pumps out put.
So how do you do it.
How do you know how much it is supplying.
The lists I have read talk about 40-1 or even 80-1, how does that equate to the pumps out put.
Thanks for any advice.
Bill Dag.".

You are right. I can stick to the facts (sometimes) and be very stubborn about that.

And you on the other hand are ??

[Suzsmokeyallan]

And you on the other hand are ??

Sticking to what I've actually tested and seen working well.

[tz375]

Happy Easter Allan, and everyone else.

[oldjapanesebikes]

And to you also Richard.

[Suzsmokeyallan]

Happy Easter to everyone too,

[rbond]

So has anyone actually answered the question? 'Where do you adjust the oil pump?' I am glad this discussion seemed to go well despite the almost totally opposite view points. On my GT500 I backed off the pump some and am using a full synthetic oil. At low speeds it barely smokes, once it warms up. When I get to about 50mph or more it 'may' smoke like I am fogging for mosquitoes and sometimes not so bad, maybe an accumulation burning off? Anyway, both plugs have the same color, have put 7000 miles on the same pair with no sign of fouling or running hot. Ran these same plugs in 100 degree, high humidity weather with virtually no sign of distress, at least for the bike, me I was dying!!!! I read Jennings treatise when it first came out. Interesting, but flawed. There are too many variables involved to make a blanket and inviolate conclusion based on Jennings findings. Some of what he said makes sense and is even true (back then, based on the oil available), however things have changed for the better in case of oil quality, so much so that you have more room to wiggle in. Each bike and riding style is different, also quality of gas, don't forget the gasoline component, it's chemical composition also affects oil dispersal and 'clinginess' in doing it's job. So, with so many things to consider, as ambiguous as all this is, everyone is right and wrong to some degree at the same time. Before anyone gets their feelings hurt, step back and look at 'both' sides from a purely logical and independent view point. I think you will see the merits of both and understand where everyone is coming from. At least in the running of oil injected Suzuki 2 strokes, (simplistically) too little, or too much is detrimental to the good health of your motor. Although no one seems to notice, for the most part all Japanese bikes are built to the absolute minimum (component quality and function) to last a few years with little breakdown. This is to make each bike as profitable as possible, make a decent reputation, breakdown eventually, so you will BUY ANOTHER BIKE. They really were not intended to last this long in continuous use, so the whole oil issue with longevity(years) is really a moot point especially from the manufactures point of view. If you still got a 30 something old bike, you have not be buying more bikes over the years. Whoa, I think I am rambling on, so I will stop here. You know, I wish we could all meet in person at one time and have a looong time together just to talk........rather than type, my fingers hurt.

[oldjapanesebikes]

And down the rabbit hole we go again !

As an aide to any discussion that may ensue, let me offer a copy of the sign we had put up in each meeting/conference room at one of the refineries I worked at as a 'test' of data quality. We found it useful in accident/incident investigations etc. to move folks up the data quality ladder, away from talking about 'what they thought' to 'what could be independently verified or duplicated' - facts in other words.



Of course, opinions and beliefs can be more entertaining .......................

[Suzsmokeyallan]

Ok the rabbit hole is in play so listen up, To reduce output of the pump you are dialing the lever setting back from the factory setting in the direction of fully off.
Start at the factory setting mark and place a felt marker dot there and one at the levers full off position.
Then make two more dots in between the first two you made for four evenly spaced dots that will do in total.
Start your first adjustment at the one just under the factory setting, and then test results from there.
Plug readings will let you know whats going on.

[h2okettle]

When I first got my bike it acted like an old shovel head Harley, leaving oil spots whenever I stopped.. The oil was dripping from the back of the pipes.. I then leaned out the adjustment of my pump arm as I figured Suzuki wanting to be safe said "more is better".... I backed the arm up till it hit the cases.. I get about 900 miles to a quart of oil, depending on the riding speed.. My last trip to California and back to Florida, I used 7 quarts of CCI in 5 days.. I rode about 5700 miles. The first 2 days I was running 75-80mph for 20 hours a day stopping for fuel and snacks. I have over 121K miles on the bike and and no crank bearing problems ever.. My trip acoss the US and to Canada to visit Allan and H2Rick covered right at 8K miles in 3 weeks riding 2 up and loaded with gear, and when I check my plugs they are a light chocolate brown.. I have over 30K miles on the plugs in the bike and they still look and run fine.. I am not a tuner or oil specialist, so I don't really know about all the ratios. I am the one trying to wear the bike out.. The GT has been my most reliable bike ever.

Allen.... Heavy smoker..... Suzuki brand !!

[Suzsmokeyallan]

Allen, thanks for giving this thread a "heads up", backed up by over one hundred thousand miles of testing.

[tz375]

Wasn't the rabbit hole a reference to Alice in Wonderland or through the looking glass. A fantasy as I recall.

BTW, Jennings used Castor (bean oil) IIRC where PB did the tests on different oils, and only the very top of the line oils like A747 are better than that. All other oils today are less than Castrol R was even back then. But we went around that loop already, so let's agree to disagree on that.

Ian, I like that chart. My only question is where does the pseudo logic based on incomplete and non-verifiable information with conclusions which are not thought through rigorously go? So often we hear of someone's experience and they conclude that a certain thing must be the cause of that effect when it is clearly not a logical deduction. I'm talking in general here, not this specific case.

It's the old story of my bike misfires so I replaced the battery and it seemed better for a week and now its as bad as it was so what's wrong with my charging circuit? When the actual problem was floats out of adjustment or jets all wrong and by the way I used race gas that I had in the shed that week because I knew it was electrical so it wouldn't matter. That sort of nonsense where the facts are not all gathered and so conclusions are wrong. It happens all the time and since most of us don't have a good understanding of say spark plug temperatures and the effect on plug colors, the "logic" is flawed from the get go.

Those appear to be the majority of cases in real life as well as in forums and I see it all the time in the corporate world where people draw the wrong conclusions because they either had the "facts" wrong or they made assumptions and filled in the blanks.

Where do those fit on that chart?

I tend to forget that US society puts great store in personal experience and stories. They are frequently regards as more valuable than any scientific study. We have actually become a society where science, like politicians is not trusted, but anyone with an opinion is. I find that interesting. I suspect that politicians are to blame there too..

It's OK though, Allan will be along shortly to have the last word

[oldjapanesebikes]

My only question is where does the pseudo logic based on incomplete and non-verifiable information with conclusions which are not thought through rigorously go? So often we hear of someone's experience and they conclude that a certain thing must be the cause of that effect when it is clearly not a logical deduction. I'm talking in general here, not this specific case.

Richard - the ones you refer to fall into the 'hearsay', 'beliefs' and 'opinions' section. From an engineering perspective, if you haven't eliminated the variables, can't unfailingly duplicate a result exactly, don't have the math or materials science to explain what's happening, can't accurately measure it, haven't had it independently validated, or independently documented then it isn't a 'fact'. It isn't unlike the discussion on this board some time ago about performance, carburettor types and expansion chambers - until someone runs some controlled tests with the test parameters well defined, and produces some actual reproducible dyno results, its all just an exchange of opinions. Some of those opinions may be much more well informed than others, and they may even be the best available guidelines or 'rules of thumb' to follow, but by definition they aren't 'facts'.

[Willgo]

Ok Guys.
First A thank you for the Knowledge and debates.
I now know how to alter the oil supply and what and where that alteration will do.

As to whether it’s a good or bad thing to reduce the oil supply I haven’t fully made up my mind.
It would appear that there are riders out there that have reduced the supply with no ill effect.
But that may be down to their riding i.e. a lot of time at on or near the max output of the pump, which you can't alter and may affect the smaller 380 more.
Another point is one would assume the men at Suzuki know what they were doing when they set the output for the oils available at that time. If that’s so, are modern 2stroke oils so much better that a reduction in supply would be what they would do now?
My experience of modern oils for 4strokes would tell me there has be great leaps forward in oil technology but they are not necessarily better to use in older engines designed for oils of their period.
But that sounds like a new question and I suspect debate.
I am minded to run the bike with standard factory settings to start then see how it runs.

Having said that I was not a fan of the 2strokes of my youth like the Brit Arial Arrow (A premix). that smoked so badly birds fell out of trees as they passed by and dripped un burnt oil from silencers (oops sorry Mufflers). But that’s something I do not remember these GTs doing unless they were in real need of an overhaul.
Once again thank you.
And I am open to advice views on 2stroke oils.
Bill Dag.