gasoline for lawnmower

Page 4 of 5  

wrote:

Used to be a LOT of injector problems on 2.2 and 2.5 liter K-Cars with TBI - and cleaning very often fixed them. They didn't block up , they leaked. Get the gum out and the pintles could seal properly when they closed, and the stumbling, smoking, and assorted other problems dissapeard.
Used to have some prblems about the same time (early 80s) with bosch L-Jetronic based systems too, where the injectors would dribble. A can of BG 44K usually fixed them up if you caught them soon enough.
Some brands of gas were better than others.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Doug wrote:

That's all a crock. If you use gasoline equipment every year there should be no problem. I never have gas or starting problems ever. It takes more than a year for gas to go bad and gum things up. I even start and warm up things in off season to keep them good.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 12 Nov 2009 09:04:19 -0500, Van Chocstraw

That's not been my impression. I don't know how you've done so well.

Well I guess that is how. I'm glad you added that or your post would have been very misleading, since you started off calling calling all of it, including the stabilizer, a crock.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I agree. A year ago I forgot to run the snowblower dry and since I normally do, it didn't have any stabilizer either. Come winter, it wiould not start. I wound up having to pull the carb, buy a rebuild kit and clean it. No question there were gum deposits inside which were the problem. After that, it started right up. So, with about 13 years of experience with no problems, having it gum up the one year gas was left in it is evidence to me that it's not a crock.
I drain the snowblower and add sta-bil to the lawn mower.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Doug wrote:

the modern engines are designed for 87 octane unleaded. Stabil in the tank if it's gonna sit over a year is a good idea. If less than a year, don't worry about it.
sounds like you were talking to an old timer that didn't know shit.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Well-seasoned? To me that says old, and old gas is the stuff that varnished up your carburetor...

If the first two are throwing you for a loop, push the mower out to the side of the road now and put a sign on it that says "FREE." Then hire your lawn mowed by a professional... It's not difficult to push the "92" button on the gas pump, or to follow the directions on the Sta-Bil bottle. You can buy Sta-Bil practically anywhere...
92 octane doesn't hurt. It doesn't help, but it doesn't hurt. The Sta- Bil is a proven product that keeps your gas from going sour by sitting around for many months.
Lead additive... That's snake oil. Even if you can find lead additive and it does do something, your mower doesn't need it unless it is really really old. Truth is lead additive doesn't do anything, and nobody sells it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 12 Nov 2009 15:51:09 -0800 (PST), snipped-for-privacy@rochester.rr.com wrote:

Lead was a way of acheiving higher octane (resistance to knocking). High compression engines will knock with too low octane, but maybe that is lessened with fuel injection (just a guess), or with a different spark timing, or maybe cars don't come with 10.5:1 compression ratios anymore.
They've even lowered the octane of gas with the same octane number. About 20 years ago I think. 92 octane used to mean one thing, but now 92 octane is the same as 89** octane used to be
**not sure of the number.
So no he doesn't need it, but it used to be important.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

The octane ratings have not really changed - in North America anyway, it's always been R+M/2 (reaserch octane plus Motor octane devided by two) for automotive gsoline. Aircraft gasoline is totally different - with the two numbers, say 85/90 being rich/lean ratings.. The aviation lean motor rating is close to the automotive R+M/2 octane in most cases.
RON, or research octane number, is a mostly theoretical number, comparing a sample of fuel to a standard mixture of "octane" and "heptane". The MON, or Motor Octane Number, is measured knock resistance using a standardized variable compression engine in a closely controlled load test to detect actual knock resistance under load in an engine.
In many parts of the world the RON was (and still is) used - In North America the R+M/2 or "road octane" rating has been used since the late 30s or early 40s.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 13 Nov 2009 01:59:06 -0500, snipped-for-privacy@snyder.on.ca wrote:

I read what you have below, but I know I was told something like my paragraph just above. Maybe even heard it on the radio. I googled a bit now and can't find anything to support my statement, however. Do you or anyone know what I could be thinking of? Was it a hoax? Does anyone remember it?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 12 Nov 2009 15:51:09 -0800 (PST), snipped-for-privacy@rochester.rr.com wrote:

It most definitely hurts, and can lead to an expensive rebuild.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 13 Nov 2009 06:38:08 -0500, snipped-for-privacy@dog.com wrote:

Well, I have several (4) decades of experience as a mechanic that re-enforces what I have been taught - high octane fuel will NOT damage an engine. High LEAD fuel can damage an engine. High lead fuel is high octane, but high octane does NOT need to be high lead.
Propane is 115 minimum AKI and unless it is run too lean it will NOT harm an engine (if the engine has hardened valve seats designed for lead-free fuel) High octane unleaded motor fuel without ethanol likewise will not harm any engine designed to run on regular unleaded gasoline.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

bullshit.
agreed. octane is basically the fuel's resistance to preignition. Going higher than necessary is a waste of money, nothing more.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 13 Nov 2009 17:37:33 -0600, AZ Nomad

Okay, you are wrong, too, then.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Name one case of an engine destroyed by too high octane fuel.
Otherwise, you are shown to be talking out of your ass yet again.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 13 Nov 2009 21:12:20 -0600, AZ Nomad

Well, for openers I didn't say any engines were destroyed. So now who is making things up and talking out of their ass?
octane = burn retardant it slows the bang down for a more even, cooler burn thats how higher octane 'cures' pinging - by burning cooler and calmer
"Cooler" also promotes carbon buildup in engines that are designed to run on lower octane gasoline.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You said: "It most definitely hurts, and can lead to an expensive rebuild."
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 14 Nov 2009 07:12:18 -0600, AZ Nomad

Yes. That is what I said. I did not, however, say what you pretended I said.
Your "challenge" was equally intellectually dishonest.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 13 Nov 2009 17:37:33 -0600, AZ Nomad

You need to understand the difference between detonation and pre-ignition. Pre-ignition is ignition instigated BEFORE the spark fires - generally from a hot spot in the cyl. This can be a sharp valve edge, glowing carbon, overheated spark plug, etc.
THAT is not detonation, and higher octane fuel will NOT prevent, or even reduce it.
Detonation is the "explosion" of the destabilised end gasses, usually farthest from the spark plug, in static pockets, due to high heat and pressure causing the hydrocarbons to dis-associate.
Octane rating indicates the ability to resist this spontaneous, uncontrolled burning after ignition has occurred., and a faster burning fuel is less likely to detonate than a slow burning fuel (natural octane, I like to call it) This is also why detonation GENERALLY occurs at lower speeds and under high load, not at higher engine speeds.
Detonation can CAUSE pre-ignition, but is not detonation. Detonation can also CAUSE pre-ignition. If cyl head temperature increases and exhaust gas temperature drops, that is the surest sigh that detonation has occured,
How, or why, you may well ask?
When detonation accurs, it disturbs the layer of air directly against the surface of the combustion chamber, and "scrubs" it off. This layer acts as an insulator, preventing the total heat of combustion from being transfereed to the cyl head and piston. Whenit is disturbed, much of the heat of the exhaust is absorbed bu the piston and cyl head, reducing the exhaust gas temperature and raising the cyl head temperature.
Now, when this happens, parts of the cyl head and/or piston, and/or the spark plug, will overheat, and there becomes a high probability that the fresh charge of air/fuel mix will ignite spontaneously before the plug fires - classic pre-ignition.
If pre-ignition happens as a precursor to detonation, it is because the spark, occuring too early in the cycle, causes cyl pressures to increase MUCH higher than normal (expansion against a rising piston instead of against a descending piston) and that pressure and heat acts on the end gasses for a longer time, making the disassosiation and detonation more likely. Pre-ignition causes a normal, controlled conflargation in the cyl - just at the wrong time. Gives you the same effect as "spark knock" caused by over-advanced timing - which again is NOT detonation - but can cause detonation.
Pre-ignition and "spark knock" can be hard on bearings and pistons - causing causing cracked or broken pistons and/or pounded out bearings and/or bent rods etc.
Detonation, on the other hand, causes burned pistons and/or metal transfer to the spark plug, and/or cratered surfaces in the combustion chamber (looks like small sharp bits have been pecking away at the roof of the combustion chamber, or the top of the piston ) and aluminum "spray" on the plug tip, and CAN cause fractured pistons, damaged bearings, bent rods, etc along with the other signs of detonation.
Detonation causes overheating as well as being excaberated by overheating.
Pre-ignition is most often caused BY overheating.
Detonation as a precursor to pre-ignition is more common than the other way, but both are possible.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 13 Nov 2009 18:15:15 -0500, snipped-for-privacy@snyder.on.ca wrote:

Wrong. Dead, completely wrong. Running High Octane gasoline in a low compression engine that is not designed for it will cause excessive carbon buildup which can lead to frozen and broken rings, cylinder scoring. The carbon buildup can also lead to pre-ignition which can trash the engine, too.
Your 4 decades didn't teach you much.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 13 Nov 2009 22:02:39 -0500, snipped-for-privacy@dog.com wrote:

Running too rich or too cold causes carbon build up. Running fuel with too much lead causes lead buildup. Running high OCTANE fuel causes NEITHER.
There is more MYTH surrounding fuel octane and the results of using octane higher than recommended for an engine than just about any other automotive or engine topic today.
Much of it is based on half-truths. A continental 85 aircraft engine, for instance, was designed to run on 80/87 octane aviation fuel (White) which had virtually no lead. It is no longer universally available, so users are forced to use either 100LL (Blue) or 100/130 (green) gas. The Lycoming O200 is another example. Using the highly leaded 100/130 will cause engine damage due to rapid lead buildup - particularly on the valve stems. Using "blue" avgas, 100LL, is less problematic as it contains significantly less lead (although still much higher than the old leaded super premium automotive gas) and can be used on these older engines with some caveats. Agressive leaning can be used to purge the lead, or certain additives can be used to keep the lead from sticking and remove lead that has accumulated (to a certain degree) Alcor TCP is one commonly used additive for this purpose. TBO on these engines when run on the highly leaded fuels is generally lower than it would be running 80/87, and Mogas STCs are available for many engines/planes to allow the use of 87-92 (minimum) octane unleaded automotive fuel - with NO ETHANOL. This is becoming more commonly available at many airports.
This is the basis for the MYTH that high octane fuel causes build-up problems and engine damage.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.