Slightly off topic, old 2 stroke lawnmower engine thoughts

[altair]

As well as having chainsaws, I also collect, and have restored a couple of old "Iron Horse" two stroke mowers dating from the 1950s and 60s.

Known in USA as "Bricktop" engines, fitted to the older Lawn Boy mowers..and were used as an outboard also, known as the "Dolphin" pretty basic engines, around 90cc, 3HP.

My question is, I use full synthetic oil in all my chainsaws/hedgetrimmer/weed whacker etc at 40:1, as they are modern engines. But wondering if synthetic is safe to use in these old school motors? We are talking points/reed valves/3000RPM engines here...lol

Or would the older mineral two stroke oils be better? I use one of these for everyday mowing here in NZ, as they do a better job than the modern mowers, so I'm looking for maximum engine protection, plus the synthetics burn much cleaner.

Not worried about oil cost so happy to use a full synthetic at the mower manufacturers original ratio, probably 25:1 as they originally used 30 weight engine oil! Or should I stick to "mineral" 2 stroke oil?

Sorry its not a chainsaw question, but still a 2 stroke engine!

Cheers

 

[T0RN4D0]

I'd go with whatever you run in your other OPE. (for me that would be 3% cheap synthetic).

I don't see a reason a better oil could hurt it. And the synthetic oils we use today are a lil better at doing the job than the stuff from 50 years ago. That's why i believe that you don't have to run it at the same ratio.

 

[xxl]

I miss the toro suzuki 2 cycle those were engines. i remenber they ran 50 -1 but they were late 80s early 90s

 

[Fish]

Why even start these mindless synthetic oil threads?

Nothing is ever settled/agreed on.

Either way, who gives a ****?

 

[John R]

Why even start these mindless synthetic oil threads?

Nothing is ever settled/agreed on.

Either way, who gives a ****?

That was a big help.

 

[Gologit]

Why even start these mindless synthetic oil threads?

Nothing is ever settled/agreed on.

Either way, who gives a ****?

You've been a member since 2001. In that time there have probably been thousands of oil threads. Do you read them just to irritate yourself?

Do they give you, in your opinion, an excuse to be sarcastic and to belittle the person making the post?

There's an easy solution, Fish. Quit reading oil posts. And quit running your mouth every time somebody who seriously wants some good advice asks an oil question.

If you quit reading the oils posts you'll be a lot happier. I know that we'll all be happier not to hear your opinion of them. And maybe some of the new guys who ask the oil questions might stick around instead of being discouraged and intimidated by the likes of you.

 

[altair]

Why even start these mindless synthetic oil threads?

Nothing is ever settled/agreed on.

Either way, who gives a ****?

I give a "****"..and its none of your damned business..if you don't like these threads, then don't read them. Go push overs somebody else's sandcastle somewhere else.

I'm interested because these motors I have are basically antiques and I want to keep them running as long as I can.

 

[Sprintcar]

Altair,

I have three Lawnboys. Two F series and a D series. All run on Stihl HP Ultra at 50 to 1 with no issues. Please post some pics of the outboard. I just received a Johnson Seahorse rated at 3 HP and an OMC at 9.9 HP. Looking forward to playing with something else.

 

[CTYank]

Some old 2-stroke mowers (I'm thinking Jacobsens) had plain bearing (the alum rod itself) big end.
As did some other oldies. They probably require more oil than 50 or 33 to 1.

We've gotten spoiled with the newfangled ones and all their needles and rollers. :cool2:

 

[FergusonTO35]

I like this thread. I think that it's best to use more oil in the mix for 2 strokes from the 50's and 60's than is used in modern equipment. Many older engines used bushings instead of roller bearings in the crank and so need a thicker lube cushion. Also the older engines may not handle heat as well as newer ones which run a leaner AF ratio and use less oil in the mix. I think that oil in the mixture helps to lower combustion temperatures in a similar fashion to EGR in a car engine, which can also help out an older motor.

 

[TheJollyLogger]

I like this thread. I think that it's best to use more oil in the mix for 2 strokes from the 50's and 60's than is used in modern equipment. Many older engines used bushings instead of roller bearings in the crank and so need a thicker lube cushion. Also the older engines may not handle heat as well as newer ones which run a leaner AF ratio and use less oil in the mix. I think that oil in the mixture helps to lower combustion temperatures in a similar fashion to EGR in a car engine, which can also help out an older motor.

I agree. I don't think oil type is as much an issue as ratio. Syn should be good for these engines, but 50:1 is probably going to be too thin.

And +1 on fish being a grumpy old bastard.

 

[z71mike]

I agree with above. The older bearings may need more lube. I'd stay with full synth though. Better lubricating properties. If you run it a little heavy, say 40:1, you should be fine. You don't need to run the full synth at 25:1, I would think.

 

[altair]

Altair,

I have three Lawnboys. Two F series and a D series. All run on Stihl HP Ultra at 50 to 1 with no issues. Please post some pics of the outboard. I just received a Johnson Seahorse rated at 3 HP and an OMC at 9.9 HP. Looking forward to playing with something else.

Sorry, I don't have one of these outboards personally, but know they were used years back. Basically a bricktop motor with different exhaust, and a shaft and prop attached. Remember seeing one years ago when I met an old gentleman who did his time repairing Iron Horse motors, he owned a repair shop and when he retired I purchased a lot of brand new C-12 parts off him, along with a friend Pete (pcamore on here).
Guess they would have been competing with the mighty 2HP Seagull outboard.

The old guy laughed, cos it sounded like someone was mowing their lawns on the lake, the distinct Iron Horse sound.

Sure they were called "The Dolphin", there was one for sale here in NZ for $20 a few years back on our big auction site TradeMe. Would have bought it as a collectors piece but freight would have been crazy for it.

 

[altair]

Out of interest, here are a couple of links of old NZ mowers with Iron Horse motors, the brown one is the very last Iron Horse made I think, maybe mid 1970s, the other a mid 1960s. The last one was sold recently, would have bought this but freight would have been $75 for a 4 hour journey. May be of some interest to you guys.


Masport Iron Horse Mower | Trade Me

Masport Iron Horse Mowers | Trade Me

IRON HORSE TWO STROKE MOWER. | Trade Me

 

[Cannon51]

You may want to do some reading here. Walk Behind Mowers - MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information
I shipped a Lawnboy 5234 to one of them and he restored it.
Cannon

 

[old 040]

i've been using echo's two cycle oil for years now, i've owned, and still own many oldies, but i do run them at a richer mix, around 32/1 with no issues, here's a pic of one of my rarest two strokes using this mix, it's a power products "free air" twin, yes, it's running in the photos..................View attachment 294734................View attachment 294736

 

[7sleeper]

Why even start these mindless synthetic oil threads?

Nothing is ever settled/agreed on.

Either way, who gives a ****?

You've been a member since 2001. In that time there have probably been thousands of oil threads. Do you read them just to irritate yourself?

Do they give you, in your opinion, an excuse to be sarcastic and to belittle the person making the post?

There's an easy solution, Fish. Quit reading oil posts. And quit running your mouth every time somebody who seriously wants some good advice asks an oil question.

If you quit reading the oils posts you'll be a lot happier. I know that we'll all be happier not to hear your opinion of them. And maybe some of the new guys who ask the oil questions might stick around instead of being discouraged and intimidated by the likes of you.

I wonder what is going on!? Fish has an absolut correct statement that in every oil thread in the last few years that I can recapitulate, has never come to a general consens. It is usually only a constant thread of statements by individuals on individual oil amounts. So what is wrong with his statement! Of course the way he packeged it is not community friendly. But the principle statement is absoluty correct!

We have never seen any proof that any two stroke run on 1:16 will run longer than on 1:100 with modern full synthetic in real world testing. We have never seen any proof that full synthetic will damage old hardware. The only evidence we know is so far that having the carb not set correctly will damage two stroke equipment. There has never been a comparison done between high speed chainsaw engines (13500rpm), medium speed brushcutter(10000 rpm) and low speed lawnmower (?rpm) engines. So it simply boils down to belief which is hardly called evidence.

The same is already going on in this thread. A bunch of guys elaborating oil amounts from 1:16 up to 1:50 using dino, semi synthetic up to full synthetic.

7

 

[sachsmo]

Oyl is oyl,

Some is good, none is bad, test on Monday.


This does get me thinking about machining a shaft for the 35HP Sachs Fichtel sled engine.

I want to put it on my old Simplicity Sunstar. It was always a good mower/blower with the old Kohler, but lacked the RPMs to seriously throw grass/snow.

Nearly doubling the RPMs at the PTO should cure that eh?

 

[67L36Driver]

My 25 y.o. Lawnboy runs 32:1 with whatever synthetic oil comes to hand. The saws have to share.

Done deal.:msp_tongue:

 

[old 040]

another classic that i recently sold................View attachment 294797..................