Well, with over 40 years experience with the stuff, MMO is very
effective at feeing up moderately stuck rings, quieting down noisy and
sticky hydraulic lifters or timing chain tensioners and conditioning
leather accelerator pump cups - among other maladies experienced by
In today's engines, it does appear to also solve sticking and dripping
fuel injectors a good percentage of the time. Not foolproof - but
always worth trying when the option is dissassembly of half the intake
system to remove injectors for proper cleaning. $9 to have a better
than 50/50 chance of avoiding $400 worth of repair is well worth it in
my experience and opinion.
It was the first thing to try on the old 230 cu inch Chevy six when
lifters got noisy (a common occurence) and quite often the last step
required. Rislone worked too, sometimes - but usually took a bit
longer - and was more likely to cause goey crud to turn to cinders in
a poorly maintained engine. (more solvent - less lubricant)
Engine (4 cyl aircraft) sitting for a year or more has a "limp" when
started - one cyl down on compression. Cyl leakdown shows 40/80 on 1,
70/80 on 2 and 75/80 on one.After 20 minutes of running - no change.
Put MMO in the crankcase and run for 20 minutes and 75/80 all across
the board. And that is not a one-time experience - just an example.
The stuff has a pretty good record for removing "greenies" from
carburetors left overwinter with ethanol gasoline, as well as
disolving varnish from carbs when used as a fuel additive - and when
added to the crankcase has a similar effect on sticking valve lifters
and timing chain tensioners
On Sat, 25 May 2013 16:39:14 +0000 (UTC), "Danny D."
The reason "premium" was mentioned is that in MANY cases, the only
ethanol free fuel you can buy IS premium.
In Canada no Shell premium fuel has ethanol added. They sell a small
enough percentage of premium that they can meet the ethanol content
regulations completely by adding 10% or less to the low octane fuel,
which when mixed with premium for the mid-grade yields a 5% ethanol
As for lawn equipment, air cooled engines have a tendancy to run HOT -
which makes even low compression engines succeptible to detonation -
so running premium in lawn equipment has long been recommended.
When grass dust half plugs the cooling fins, lawn mowers run even
hotter than normal.
I agree that anything that makes an engine run with higher
compression, higher heat, or advanced timing (further than
spec), will increase the need for a fuel that resists
Of course, the real solution is to clean the piston heads
of carbon deposits; ensure the cooling fins aren't blocked;
and make sure the timing is to spec - but - if these things
are off - I do agree that an engine can knock.
And knocking, if it gets bad, can ruin engine journals,
among other things.
Around here quite a few dealers have been recommending premium - and
when I worked for an Ariens dealer back in the late sixties we
recommended premium on the mowers - which also required popping the
heads off to remove lead deposits every year or so. Prevented taking
pistons out when (not if) the fins got plugged on a hot day.
Unleaded fuel solved the deposit problem, by and large. Some of the
newer engines are less prone to plugging the fins and shrouds due to
better housing design - but then just when they more or less solve
that problem, they up the Compression Ratio with the OHV engines, and
the fixed jet smog carbs run the engine on the lean side -
particularly with ethanol fuel - so the octane requirements go up
again - making premium fuel , particularly if it is ethanol free like
Canadian Shell Ultra - a sensible option.
On 05/27/2013 08:59 AM, firstname.lastname@example.org wrote:
Surprisingly, it appears that it was still legal to sell in the US until
1995, although I don't remember seeing it being widely available after
the early 80's. Likely, since road vehicles manufactured after the
early 70's couldn't run it, there wasn't much market for it so it was
slowly phased out as demand dropped.
replace "roosters" with "cox" to reply.
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