2T Oil

[Andy_C]

No doubt been asked many times before.

My usual source of 2T oil has ceased to exist, they now only stock 2T Fully Synthetic "Racing" oil, where I was using Semi Synth.

I have been told that full Synth should be avoided in a road going bike as it does not get hot enought to warrant full synth, and full synth tends to gum up the internals - any thoughts ?

[Puffs]

IMO a fully synthetic has a narrower & better defined composition, giving a higher temperature stability. That means there are fewer long molecules that break down at the higher temperatures. That can give more reliable lubrication, particularly in cases where the oil is exposed to high temperatures over a long period of time. A prime example of that is when it is used (and re-used, 'long life') to lubricate the shaft of an exhaust turbine, in for instance a modern turbo engine, but also under racing conditions very high temperatures can occur. And the better temperature stability can also translate into less carbon deposits in the head, on the piston crown (also inside), and in the exhaust.

Now to what extent that better lubrication is required in an MZ (or any old two stroke) in normal road use, I don't know. But I do think 2T bikes were used long before synthetic oil was around. Synthetic might help, a bit, but I think failures are rarely caused by the oil having degraded under high temperature, and that lubrication-wise you'll also get by with mineral or semi synthetic oil. Yet having less carbon deposits remains desirable.

I think using fully synthetic won't hurt your bike, and that it has advantages, but if the benefits are worth the extra money is anybodies personal choice. In these old two strokes I use a semi synth I could cheaply buy a batch off.
Note: don't be tempted to pre-mix leaner "because this is a very good synthetic oil".

Any other thoughts, please?

[Andy_C]

Puffs - I pretty much agree with your thinking.

I have found another source of Mobil 1 Semi Synth so no problems any longer, been using this stuff in my 2 strokes for years and dont really want to change.

Cheers.

[Puffs]

Just an update; I was running low on stock & bought this:

Mannol 2-Takt Plus.jpg (52.39 KiB) Viewed 85 times

Haven't tried it yet, but specs are fine.

[Blurredman]

I think, concerning old 2t motorcycles that I am the only publically outgoing confessor of using mineral.

I use the cheapest mineral I can find, and in bulk. I ride my MZ's for tens of thousands of miles. Pre mixed at 30:1 and don't have concerns.

Weigh up the cost of oil vs re-builds.


My brother (also an MZ rider) and I have also been known to use motor oil and also bean oil too just for fun.

[Puffs]

Yeah, sure, but look at that - with pure Hamburger oil you can't go wrong!


But seriously: no, you're not the only one in the mineral oil camp. There are quite a few more. Reasons mentioned are in the areas of economics, technical & stylistic. Anyway, it's a choice, as is much in life.

Personally I feel a little embarrassed when I leave a thick blanket of white smoke when I ride the bike a bit more enthusiastically, and JASO FC or FD help to prevent that. A little. Then it's just puffs.

[Blurredman]

People put too much emphasis on the quality of oil.

Whether it comes to buying the most expensive motor oil for a car, or synthetic oil for a motorcycle that hasn't really changed much in design since the 50's.. When they would most likely have run SAE30 or something.

Flush oil, as is advertised these days, is good oil and I use it sometimes for a service interval period. Even the cheapest oil I have bought doesn't have bits in it anymore, either..

I feel the opposit in regards to smoke.. When I am throttling it, I want people to know.
And.. Either way.. even if it looks like I have a disregard for the environment, the old diesel taxis that run around me always have lots of blue, or black smoke even in the most gentlest of throttles. The world is not a clean place, and I like to remind people of that.

I ride through the city every day, and that puts a bit of a backlog of unburnt oil, to which I like to clear out on a section of dual carriageway where I pretty much pin it. I am normally disapointed if there is little to no smoke..

[MichaelTorre]

Having been a motor technician for 27 years I can tell you that motor oil quality matters! I've had plenty of before and after opportunities.

The micrometer does not lie. Put the good stuff in the good stuff !
M

[Andy_C]

Having been a motor technician for 27 years I can tell you that motor oil quality matters! I've had plenty of before and after opportunities.

The micrometer does not lie. Put the good stuff in the good stuff !
M

Tend to agree, I always like to use a decent quality oil, hence I use the Semi Synth in my strokers.

Happy to say that I have found a new source of Mobil 1 Semi Synth which I shall be sticking to happy days

[Puffs]

Many people appear to use Mobil 1 in an MZ.

I believe that in racing just about everybody uses/used synthetic 2T oil. In racing you do what you can to prevent a DNF and/or avoid costly repairs to your 220+hp/L jewel, and normal economics do not really apply.

But in what we're talking about here, using low powered 2-strokes (+/- 80hp/L) on the public roads, the drivers are a bit different, at least for me they are.

Michael, you say "I've had plenty of before and after opportunities. The micrometer does not lie."; can you please explain a bit more?
Blurredman, you say "Weigh up the cost of oil vs re-builds."; can you please explain how that works?

Does anyone know of any reported relevant testing in this area? I mean real world practical tests, so other than those done for certification (like 'API TC', 'JASO FD',...)?

[Blurredman]

Puffs:


Let us say it costs £50 for new piston and rings, and £50 for re-bore (if needed..) this is after 20, 000 miles of abuse, and i mean serious engine abuse of forgetting oil, running lean, thrashing it, bad timeing- so running advanced etc, but you used Mobil 1 at let's be generous at £10 a bottle. Depending on whether you use the pump or pre-mix the longevity of the oil may vary, but if you're like me and use 30:1 pre-mix then that's £5 a fuel up. I normally cover 200-250 miles per tank, let's say 225.
I would have filled up almost 90 times (let's make it simple here) in that 20,000 miles. It would have cost £just under £450 of 2t oil.

Why bother? £50 a piston, slap it in when it needs one. Whether that's at 5,000 miles or 40,000 miles. Even if your crank is gone too, because of potentially flying metal penetrating crankshaft bearings, a total engine re-build is half the price of all that oil. At my current price of £1.60 of 500ml of oil per fuel up, it costs me just under £150

Possibly false ecconomy, but.. I don't mind re-building engines. The price difference is thus:

How much does it cost to keep the engine running in it's current state?
How much deos a complete engine rebuild cost, if required?
How often would I have to re-build?


To weigh up the cost of the oil and the longevity of the engine vs how much it costs to repair the engine. Bearing in mind that on one particular machine I had done 20,000 miles on a premix ratio of 30:1 on cheap mineral oil before even opening up the top end and there was not as much carbon as many would have been led to believe. As I see it, no one would have used synthetic in 1980 ish. What I would have been using would be the foloowing oils, what ever would have been cheapest on the shelf:

Caster bean oil,
Two stroke mineral oil,
Used 10w40 oil,
SAE 30 oil.

[Puffs]

Thanks Blurredman, I see where you're coming from, and I appreciate it's a choice.

Economically the main issue is: how much longer can you ride between an overhaul if you use expensive oil, and in what way does the choice of oil impact the cost of the overhaul. But the answers to those questions are very hard to give. It may vary, and it will to a large extent depend on other factors (particularly riding style). And there are other costs you could include, like the cost of recovery of the bike & you after breakdown, or the cost of you not getting where you wanted to be, and indeed the cost of labour; for each to take his own view on.

Btw, I have never used Mobil 1, I just hear that several other people do. You know what my oil costs.

[MixP]

Just joined so I'm catching up on posts and oil does interest me. I started riding in 1968 on a Lambretta TV175, I ran that on Bardahl oil, then a Sakakaki 500 triple that I used Filtrate oil in because the Bardahl was black and obscured the oil window. Lots of two and four strokes followed and they were always run on whatever was the best oil I could get.
Three years ago I was half-way through a five month round Britain trip on a Jawa350/Velorex, this was driven very hard at times, two adults and lots of luggage including a crossing of the Bealach na Baa. I used Rock Oil fully synthetic and the only problem was a holed piston caused by an inlet rubber splitting. Me, I think paying for the best oil is a good investment.

[Andy_C]

Indeed I tend to err on the side of decent oil hence I stick with the Mobil 1 semi synth.

My other 2t bike is a "Sakakaki" H2, before that I had a KH 500, both of which I run on the Mobil 1 Semi Synth.

Sakakaki parts are getting hard and expensive to get so it makes sense to run it on some half decent oil, with the MZ I just want to minimise time between tearing it down.

End of the day, it's each to his own.

[Puffs]

Yes, that it is.

Everybody wants to avoid/delay the hassle from a breakdown/failure, and we all want to pay as little as possible (in total costs).
But even then, the choice of 2T oil is not straightforward, because the link between price & performance of oils is not so clear. If you pay twice as much for your oil, that does not guarantee you can do twice as many miles before your next overhaul, or whatever the number is. Hopefully a more expensive oil gives a longer service, but how much longer remains to be seen. And maybe something not related to oil happens, like a hole in the piston.

If it matters to me, or if parts are expensive, I tend to err on the side of caution and use a fully synthetic quality oil. My old low-powered 2T bikes get a cheap oil with decent specs, low on smoke & carbon. If I had a Kawa triple (+/- 120HP/L), it would get good oil (probably a cheaper fully synth, or maybe a quality semi-synth like Mobil 1).