what oil should i use in my seagull?

[headdownarseup]

All of what i have managed to show you is mostly to do with car engine oils.
What I cannot find right now is any specific viscosity ratings purely for 2stroke engines that we use in outboards. I will keep looking, but I can imagine that there,s probably not going to be much in it however.

My point with the dilution into fuel was that the oil starts out being 1 viscosity, (whatever that might be) and by the time its mixed with fuel it's now very thin indeed.
For the record,all of your old fashioned oils have been tampered with now anyway to comply with certain regulations globally.

2stroke oils come from the same base stock oils that get pumped from Mother Earth. The chemistry is then added, its bottled up as brand x and sold on the open market.
The expensive stuff is completely different to any base oil as it's entirely man made. Fully synthetic, with all those different additives.
Semi synth has a blend of oil and new, varying from 75-90 per cent mineral oil with some clever chemistry in the additives to make up too 100 per cent.
All in the videos if you look

Jon

[Keith.P]

Try this.
http://www.belray.com/2-stroke-lubrication

[headdownarseup]

Not quite what i was looking for Keith, close though. Thanks anyway

This guy is obviously into his snow-mobiles, but there's a bit in here that's relevant
http://www.3cyl.com/mraxl/oil-2T/2-cycle_lubes.pdf


This guy is more on our wavelengths with vintage engines just like a seagull.
http://www.oddjobmotors.com/tt5_2-stroke-oil.htm

This one perhaps covers the best of both worlds. Mention of 20 weight as a mid-viscosity, which i'd say is still pretty thin for an oil that's going to get mixed with petrol.
http://www.saltwatersportsman.com/two-s ... shing-boat


I'm still looking for that "something special"
or for you older guys that "eureeka" moment.

Bear with me

Jon

[headdownarseup]

Another bike related video, but more down my avenue of thinking with sem-synths. The best of both worlds.

https://www.youtube.com/watch?v=HBiBF6krqXQ


But, still not quite what i'm looking for to help you older guys.

Jon

[headdownarseup]

This one is a bit more of a balanced argument

https://www.youtube.com/watch?v=bdTFtEKKa8k


but still not what i'm looking for

[headdownarseup]

This one is a bit closer to what i was looking for.
Substitute camshaft for crankshaft/con-rod/plain crank bush in a seagull engine, and this is the sort of chemical make-up the older types of oil once had.
https://www.youtube.com/watch?v=ibXFpoBhkyE
The older fashioned oils ( straight mineral with high zinc content) don't seem to be available any more. Not as you used to know it. It's had to move with the times. Same with everything else i can find (so far)
https://www.youtube.com/watch?v=ibXFpoBhkyE

Mineral oils, whichever way you want to look at it is NOT THE SAME as it used to be 30-40 years ago. All you older guys have probably been using a modern variant for quite some time now, without you knowing it Yes it will still say mineral blah blah blah, good for older engines blah blah blah, excellent protection at all temperatures blah blah blah, but it's got modern additives blended into it. Some of those additives are good, and some are not so good. Some oils are better than others, that's why we have a choice, and ultimately a personal preference.

My preference is with a semi-synthetic oil for my seagulls (not fully synthetic) which for my money gives me the best of both worlds, a bit of old and new technology working in harmony.


In a nutshell, what you end up buying on the shelf that's labelled as 2stroke oil or TCW3 etc. has already been stringently tested, has to pass various tests and so on before it's allowed to be sold on the open market.

If any of this oil was complete garbage, we wouldn't be able to buy it in the first place.



This debate will always rage on for years to come.
With any luck, what i've shown you might help a tiny bit when it comes to the slippery stuff. The rest is down to you. Find something you like and stick with it.



Jon

[Keith.P]

I think the underlying question is not so much what oil do you use, that depends on how much you are willing to pay for it and how much a tree hugger you are, as so many types are on the market, and one can say, this is better than that.
The question to answer is, how much oil do I use.
Oil is better now than back in the day, but back then they didn't have 2-stroke oil at all for any motor, as they used engine oil and that is what a seagull used back then and guess what, thousands of them are still running to this day, so not much wrong with the oil back then, it did its job.
Yes all oils have improved over the years, but anyone with an expensive engine will be using the original weight/grade of oil, not multi grades or hyper grade oil, they are no better.
2-stroke oils are better as far as cleaner burning and more environmentally friendly and designed for modern 2-strokes, would anyone class a seagull as a modern 2-stroke engine.
Jon, when you used your Marston, what make of 2-stroke did you use, obviously the much better modern stuff, so how much 25:1 or 8:1,10:1?

[headdownarseup]

That was actually a bottle of oil from A-J's shed and not one of mine. Couldn't tell you what it was, but probably a modern type i guess. Green colour to it but definitely an outboard oil, with tcw3 on the label.

It was running at 8:1 when it was in the bin of water, and as you can imagine there was plenty of smoke too.(shame i haven't got any vids of that yet, i think Allegra might have somewhere on her phone)
This little Marston of mine isn't going to get converted or anything daft like that. It will be kept as you see it, albeit tidied up here and there with a paint job and new shiny chrome, but more importantly whenever i do get to use it, it will be running an oily mix around 8 or 10:1 just to keep up the crankcase pressures a bit.
I use the same heavy mix (10:1) in all of my 102's as well, and so far they've proved themselves as reliable and strong runners.

The ONLY difference here is the oil i use. Nothing else has changed from the seagull manuals as i've always followed this to the letter.


I'm still looking for viscosity ratings on tcw3 oils just to see if i can answer a question from a bit earlier. (i can't believe newer oils are any thinner than older recipes in the dinosaur range (ahem) sorry, straight mineral range)

Jon

[headdownarseup]

Came across this which kind of touches on some of the finer points that might be happening with our older seagull engines.
Larger bearing clearances and thicker oil etc.

https://www.valvoline.com/about-us/faq/ ... cosity-faq

not quite what i was looking for

Jon

[headdownarseup]

or there's this one


apparently, according to this guy a typical 2stroke oil is 20weight or similar to a SAE30 grade oil.
http://ask.metafilter.com/214803/An-ina ... -lubricant


I'm getting the opinion there is no "official" viscosity rating for these modern types of tcw3 oils.
Reading back through everything i've posted there is only 1 other reference to tcw3 oils being a 20weight.
Is this new stuff any thicker or thinner than older recipes? (remember that oil film strength is quite an important thing to have in our little gull engines even if it has been watered down by the fuel)


still looking


Jon

[Charles uk]

20 weight is less viscous than 30 weight Jon, by quite a bit!

Now here's the reason why that is important.

I've had a look for the book where I kept the records for all the early motors (JM ignition) that I was investigating for excessive main bearing wear, but no luck as yet, though I did find the record for 1 SD crankcase that I was going to use for a racing century I was planning on building (big transfer notch).

This one wasn't that bad, not clicky,but spare due to very dead cylinder.

I measure the main bearings & crank in 4 positions, (1) 1/4" below top of top main bearing, (2) 1/4" above bottom of top main, (3) 1/4" below top of bottom main, (4) 1/4" above bottom of bottom main.

As will be seen from the clearance details in the picture, all of these JM ignitions wear the top main bearing far more than any of the later ignition flywheels, when new theses bearings were reamed to give an oil clearance of 1.5 thou, so 3 thou difference between the crank & the bearing,
These bearing seen to get clicky at just under 10 thou & I've seen them at nearly 12 still running.

At 12 thou though you might need SAE90 to fill the gap!

If the younger generation understood how the lubrication system of a 2-stroke worked they'd realise that the fuel oil mix viscosity is only important to the main jet!

[headdownarseup]

this one's quite interesting, another big name when it comes to oil.

(i actually use this "EDGE" in my 50cc moped too. I like it. Works really good)

https://www.youtube.com/watch?v=Y5ud7jM5gPg

[headdownarseup]

and now improved! Is this a future replacement to the zinc in older recipes i wonder?

https://www.youtube.com/watch?v=xFZ5bO-e2Bo


I hear what you're saying Chas.
My interest in newer oils is to see if there's any real point in carrying on using an already worn/worn out engine that's done god only knows how many hours of work. If these oils really can do what they claim they can do in preventing (or rather slowing down) any further wear, i think i speak for a great many of us out there that are NOT RACERS and have shallow pockets when i say this is more about keeping something going that's already in a fragile state and (hopefully) trying not to do any further damage. Your average seagull user probably isn't interested in your findings as they probably haven't got the first idea about what those numbers mean anyway. (just saying, so don't take it the wrong way) Give technology a chance once in a while and let the boffins do the hard stuff.


I don't think you can ignore the fact there are plenty of folks out there that are more than aware just how worn and out dated these little engines can be nowadays. We talk about it almost every week somewhere here on the forum.

It seems more and more people are interested in how to convert an old (pre 78) gull to run on 25:1 with less smoke without knowing what might happen in the long run to their prised possession. Oil is only 1 small part of the equation. There's definitely more than meets the eye with this oily stuff that probably a lot of folks hadn't realised. Some good stuff is bound to come out from all this technology eventually. But unfortunately there will always be people that will have their own opinion and god help anyone that gets in their way because they're right all the time. You know the sorts of people i'm talking about don't you. The "know-it-alls".

I'm trying to keep this fair to everyone with a balanced argument to both sides of the question.
What is best when it comes to oil in my seagull?

Jon

[headdownarseup]

Looking into viscosities a bit more in the "dino oils" and came across this.
What i'm really trying to find is some discussions about how old and new compare in real world situations, and discussed by true experts in their field. No bs, just the facts, then we might start to get somewhere.

http://www.viscopedia.com/viscosity-tab ... ty-grades/

Mixed views in here
https://www.bobistheoilguy.com/forums/u ... ber=482832

this one seems to be more of a balanced and properly conducted series of tests. Interesting "test mule" though, but fairly relevant. Use the hyperlinks too, they're good as well
http://www.ultralightnews.com/features/oiltest.htm


still looking

Jon

[tambikeboy]

20 weight is less viscous than 30 weight Jon, by quite a bit!

Now here's the reason why that is important.

I've had a look for the book where I kept the records for all the early motors (JM ignition) that I was investigating for excessive main bearing wear, but no luck as yet, though I did find the record for 1 SD crankcase that I was going to use for a racing century I was planning on building (big transfer notch).

This one wasn't that bad, not clicky,but spare due to very dead cylinder.

I measure the main bearings & crank in 4 positions, (1) 1/4" below top of top main bearing, (2) 1/4" above bottom of top main, (3) 1/4" below top of bottom main, (4) 1/4" above bottom of bottom main.

As will be seen from the clearance details in the picture, all of these JM ignitions wear the top main bearing far more than any of the later ignition flywheels, when new theses bearings were reamed to give an oil clearance of 1.5 thou, so 3 thou difference between the crank & the bearing,
These bearing seen to get clicky at just under 10 thou & I've seen them at nearly 12 still running.

At 12 thou though you might need SAE90 to fill the gap!

If the younger generation understood how the lubrication system of a 2-stroke worked they'd realise that the fuel oil mix viscosity is only important to the main jet!

The teacher always tried to encourage me to learn algebra don't know why . As I've no intention of going there. .