Amsoil- 100:1?

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RIDE-RED 350r

RIDE-RED 350r

No wing, no prayer
Joined
Sep 5, 2014
Messages
520
Location
Blossvale NY
I'm gonna use up some Dominator i have, but nothing that might sit for a little bit.....i've heard stories about rusty bottom ends. Not sure if its true but it was on the internet so it probably is.[emoji1]


I USED to run Dominator religiously in my 250r. Never ran Ethanol fuel and store the machine indoors year round. After it sat for about 6 weeks, I tore her down to do the ESR big bore and I was astonished and pissed off at the amount of fine corrosion I found on the crank, cylinder wall, rod, crank bearings and just about every steel part in the crankcase and top end. And there was in fact a good puddle of oil in the base, which is good. The best way I can describe it is that it was kind of like brown dust, and most of it simply wiped off..mainly crank, bearings, etc (which were replaced anyway for the build). But the corrosion left a sort of shadow or staining in the cylinder wall..

I am not the only one who has experienced this phenomenon with Dominator oil. And I have since quit using it and switched to Maxima 927 castor oil after much research and seeing so many well known 250r specific builders recommend it for the big bores in all but cold weather conditions. I have had my top end off after the machine sat for a season and have found zero corrosion since switching to castor oil in my R. I'm not saying Dominator doesn't lubricate well, it does... But it has very little in the way of corrosion protection..at least in my experience...
 
bwalker
Joined
Jun 3, 2002
Messages
13,917
Location
Montana
I USED to run Dominator religiously in my 250r. Never ran Ethanol fuel and store the machine indoors year round. After it sat for about 6 weeks, I tore her down to do the ESR big bore and I was astonished and pissed off at the amount of fine corrosion I found on the crank, cylinder wall, rod, crank bearings and just about every steel part in the crankcase and top end. And there was in fact a good puddle of oil in the base, which is good. The best way I can describe it is that it was kind of like brown dust, and most of it simply wiped off..mainly crank, bearings, etc (which were replaced anyway for the build). But the corrosion left a sort of shadow or staining in the cylinder wall..

I am not the only one who has experienced this phenomenon with Dominator oil. And I have since quit using it and switched to Maxima 927 castor oil after much research and seeing so many well known 250r specific builders recommend it for the big bores in all but cold weather conditions. I have had my top end off after the machine sat for a season and have found zero corrosion since switching to castor oil in my R. I'm not saying Dominator doesn't lubricate well, it does... But it has very little in the way of corrosion protection..at least in my experience...
Castor has even worse potential corrosion issues than ester based oils like dominator.
 
the_old_curmudgeon

the_old_curmudgeon

ArboristSite Lurker
Joined
Dec 26, 2013
Messages
43
FWIW, I had an Evinrude outboard (yes, yes, I know not the same as a saw) that called for 100:1. The original owner actually did burn it up at that rate and it was rebuild under warranty. I bought it lightly used from him and mixed it at 50:1 like the rest of my OB's and never had a problem. After a couple of years OMC went back to recommending 50:1 for all of their premix motors.

Not the same as a saw but with some of the same concerns, what OMC discovered was that while there was generally sufficient lubrication at runtime with 100:1 mix there wasn't always enough of an oil coating left behind to prevent rust when the motor sat idle for extended periods. OMC put out a service bulletin which included instructions that outboards that came in for service would have the 100:1 stickers mounted near the gas line removed with the customer being told to switch to use 50:1 mix. I think they started 100:1 with 1986 models and by around 1991 had switched back to recommending 50:1.

The VRO systems on their larger outboards became pretty notorious for eventually failing as well so it became common to just bypass the VRO system and mix yourself at 50:1.

100:1 was nice when trolling because you had less smoke and less problems with oil loading/plug fouling with the engine running at or just above idle for long periods of time.
 
porsche965

porsche965

Addicted to ArboristSite
Joined
Oct 3, 2008
Messages
1,997
Location
N.E. Ohio
Nope haven't felt well at all lately. However that has nothing to do with the fact Saber mixed at 100:1 is absolutely the best performing mix I've used, I could even feel a boost in power. I mean everyone knows less oil means more power, what are you thick in the head or something.

And here all this time I thought Saber was only good for keeping dust down on driveways.
 
Bwildered

Bwildered

Tree Freak
Joined
May 26, 2015
Messages
12,572
Location
33' South
I know of two different people that seized a hand held blower and a Lawn Boy mower on Saber @ 100:1. I would use it at 50:1 or more, but never at 100:1.
you don't have to sit around here for very long to see a story of a 2t seizure at richer oil ratios also, any mechanical defect that will cause a seizure in a motor will happen twice as fast in one running less oil & a bit longer in one running conventional mixes.
fanks
 
bwalker
Joined
Jun 3, 2002
Messages
13,917
Location
Montana
you don't have to sit around here for very long to see a story of a 2t seizure at richer oil ratios also, any mechanical defect that will cause a seizure in a motor will happen twice as fast in one running less oil & a bit longer in one running conventional mixes.
fanks
The lawnboy duraforce motors have very weak rod bearings and scatter them regularly. The duraforce calls for a tcw3 oil 32:1 and that's all I would run in one. I use penzoil syn or yamalube 2m at the reccomended ratio.
 
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