300:1

[sILlogger]

i do believe that i would trust it. there are people running around in white coats in a lab somewhere that are alot smarter about the logistics than i am. they build it and i run the sh*t out of it. i might be a lil' leary but ill try about anything once

 

[bwalker]

At a later point in time did a 2 stoke synthetic oil exist? It's the same progression, and there are still things to be invented.

Syn oils and high oil ratios are not the same issue. Opti for instance is a mineral oil, yet they spec a 100:1 ratio. Yamaha outboard oil isnt a full synthetic, and its speced for 100:1 use and on and on.
Point being, its not synthetic oils which enable oils to be run at high ratios. Its the viscosity of the base oil and the additive package used.
Formulating a mineral bases 100:1 oil is fairly easy just add high quantity of bright stock and ZDDP.

 

[mattinky]

Not a chainsaw application, but one of my riding buddies has been using Amsoil 100:1 for about 3 years in his KDX200 with absolutely no problems whatsoever, so yeah, it's for real and it does work. Matt

 

[Mr.]

HAHAHAHA If you guys think you make more power with less oil.... GO AHEAD. It's just not so. It's just like guys leaning out their motors to make them cut faster. Just don't work.

Fred

 

[Al Smith]

Trust it,one word,no.

 

[Stihl Crazy]

I use Stihl oil at 32:1. I went to that ratio in 1995 when I got my first Dolmar 115. The dealer recommended it. I have never had any problems. Was back to the dealer last month. He couldn't believe I had over 1000 tanks on a 5100 with no trouble. He said every one he had needed topend work in less than a month. He wanted to know what ratio I was using and I said still 32:1. He told me it was too much and he was using 100:1

So my saws run, his don't--32:1 vs 100:1, I think I will stick to what works for me.

 

[jhellwig]

Less oil will provide for more power to a point. Less oil means less weight on the rotating mass there fore less force to keep it moving. It may be a very very small gain but it is there. As long as the oil keeps the bearings properly lubed why use more oil? As far as heat goes it could be the opposite of 4stroke engines. More oil in a four stroke means more heat. But in a two stroke that could mean less because you could be moving heat out with the extra oil.

I might venture to say that bigger saws need less oil than smaller ones. More fuel moving through the saw mean more oil. That is probably true to a point.


Then after all if it still does the job with less oil then that means less emmisons. Less oil might mean that you can still get you old non epa controlled engines for a while longer.


I would also garuentee that there is a margin or error in there also. Stihl might say that 85:1 is good but I bet it is still more than the motor actually needs just to cover all the other variables that can affect operation.

 

[precaud]

I have it from a good source inside Stihl back in Virginia who is telling me that the new synthetic that they are selling actually runs best at 85:1 but will not tell the public this becasue it will not sell.

If true, this sounds like an engineering/marketing disconnect inside Stihl to me.

Please define "runs best" before I decide. I'd accept it if they proved that it ran smoother, had more power, and lasted longer. Otherwise, I doubt it.

 

[Stihl_Learning]

I read this thread and it dawned on me, that i might be the exception rather than the rule.
But, I don't care what the ratio is providing its safe. I buy Stihl brand oil and run nothing but Stihl oil in my Stihl products. if the manufacturers say 50:1 I mix it 50:1 if it said 100:! I would mix it 100:1
I will say it is nice that all of my Stihl products take the same mix.

When I had Mercury outboards I used Mercury oil. When I had Johnson's it was Johnson oil. I find comfort in the fact that the company has designed the engine and the oil.

I am considering a change to synthetic oil but it will be Stihl brand and mixed at 50:1 until Stihl themselves recommends a different ratio.

I know a lot of you prefer different ratios and are probably smarter than I am when it comes to oil but I gotta dance with the one i brung

 

[PES+]

If it said Lawn Boy...........

I still laugh about that with the canadians....they FREAK OUT when I show them zero smoke push mowers running 4000 RPM and only dropping to 3000 in tall damp grass

 

[bwalker]

Can you safely spin a Duraforce to 4000 rpm? The service manual I have says something like 3400 is the max.

 

[PES+]

No...they blow up instantly

I get ten bucks a piece for the Canuck carcasses

Run them @ 3400 RPM and on the 32 to one

 

[bwalker]

Its funny you brought LB up as I am putting a short block in a Lawnboy comercial right now. The guy that mows my lawn hit somehitng with it hard enough to break bend the crank. The mower stillr an, but it vibrated like hell.
Now that It together I need to set the air vane when it warms up. If 4k is safe I will do so as it always seemed anemic compared to my old LB.
32:1 on Yamalube 2m has worked great in all my LB's.

Edit: the max rpm spec for the Toro snow commander(uses the same basic engine is 41-4200... Looks like 4k is safe.

 

[PES+]

Make sure the LB is a needle big end as some I have seen are sleeves like the late Tecumseh 2-strokes (yuk)

I would run 40 to one or more in a sleeve and only lower RPM

Is this one the Suzuki Engine or the later OMC?

 

[bwalker]

OMC? OMC hasnt made engines ofr lawnboy for years. This is a Duraforce motor, which is made by Toro. The big end rod bearing is a cage less needle bearing that run s on a silver/babbit shell type bearing instead of running on the crank

 

[PES+]

I meant the OMC design.....the whole shebang was bought by Toro from OMC they produced and improved some of the motor design but stopped marketing the 2-strokes

I have seen some Lawn Boy Commercials with Suzuki 2-strokes which is what Toro used for their 2-strokes before the Lawn Boy purchase

 

[PES+]

My favorite 2-stroke push type mower engine was the Briggs that I last saw used on the Husqvarna Ultima or whatever they were called

 

[bwalker]

I have never seen a Zuk powered LB. When I bought my 2004 model commercial I had originally wanted a Toro commercial with the Zuk motor, but I couldnt locate one as both the Duraforce and Zuk where discontinued in the same year.
The Zuk is better if for no other reason than the carb is a metal Mikuni carb, VS the plastic POS on the LB. I also much prefer the Toro wheel setup, but I cut my teeth on lawnobys so the staggered wheels dont bother me too much

 

[PES+]

I can't recommend upping the speed if you are doing it for someone else for liability reasons Blade tip speed needs to be to factory spec so you are covered if something gets thrown from under the deck or out the shute and hits someone/something

I see commercial guys all the time run without chutes and deflectors here
and they don't pick up before they mow......accidents waiting to happen

 

[PES+]

I can't recommend upping the speed if you are doing it for someone else for liability reasons Blade tip speed needs to be to factory spec so you are covered if something gets thrown from under the deck or out the chute and hits someone/something

I see commercial guys all the time run without chutes and deflectors here
and they don't pick up before they mow......accidents waiting to happen

You can spend some time on the gov and keep them from dropping too much with careful adjustment and slight over speed on recovery