View Full Version : fuel mix

03-29-2000, 09:29 PM
I was just wondering what fuel/oil ratio everyone uses in there 2 cycles. Also what octane you run.

03-29-2000, 09:40 PM
Use the oil/fuel ratio and octane specified in the manual, and you'll have no problems.<p>----------<br>Jim<br>North central Indiana

03-29-2000, 10:01 PM
Every engine that I've seen on small stuff is set up for 87 octane unleaded presently. As for oil, I use Amsoil 100-1 synthetic two stroke. One mix for everything, no more 2 or 3 cans of different mixes. Two years on this stuff now and NO failures. Also, where trimmers used to be VERY hot after trimming almsot steady for a full tank of fuel they are now noticeably cooler when you get done. The synthetics claim to run cooler, in my own observations they live up to that claim, both in 2 stroke and 4 stroke air cooled engines. In addition, with synthetic oil in the mowers I change once a season with a filter change at the halfway point.

03-30-2000, 03:37 PM
I have heard that using a higher octane also helps the engine run cooler... it doesnt make sense to me. My husky saw says to run NO lower then 92 octane or it will run to hot. I have also worked for people who use strictly 94 in everything and one mix for everything as well.

little green guy
03-30-2000, 03:46 PM
I use No smoke two stroke which is a synthetic oil and works for all ratios. I also use 87 octane gas in everything.

03-30-2000, 05:45 PM
I just finished taking a small engine class, and it verified what I'm doing. I use one mix for all my two strokes (otherwise I'd have 6 different cans of fuel mix). What you have to do is mix according to the machine using the most amount of oil per unit of gas. I have machines that run anywhere from 50:1 to 25:1 gas to oil, so I mix 25:1. The only downside is that, in the machines that want a leaner mix, you may get carbon buildup in the head, but that can be cleaned. That way you know that every machine is getting the oil it needs, while some are getting a little more.

03-30-2000, 06:11 PM
That was very informative.. thanks, but what about octane???

03-30-2000, 06:52 PM
AVgas 100LL (aviation fuel 100 octane low lead) + string trimmer = BOOM<br> <br>Just a little story I'd thought I'd share (and no, it wasn't me, a friend)<br>

03-30-2000, 08:47 PM
Ouch that sounds like it might have killed some grass!!! jk

03-31-2000, 01:01 AM
The octane rating basically relates to how much the fuel mixture can be compressed before it will combust on its own without spark. A lower octane fuel will detonate sooner than a higher octane fuel. Detonation is when the fuel combusts on its own. Detonation is not a good thing. If you've ever driven an older pre fuel injected carburated vehicle, and you hear a knocking sound under accleration or a pinging sound, that's detonation. It occurs when ignition timing is too advanced or running to low grade fuel in a engine with high compression.<p>A big misconception is that a higher octane fuel will make a vehicle perform better. Simply put it won't. If a vehicle is designed to run on 87 octane fuel, and you feed it some 92. All that you accomplished was spending some extra cash. <p>Octane simply is a function of how far a fuel mixture can be compressed without igniting.

03-31-2000, 06:09 PM
matt, every machine I have purchased for 20 yrs has stated the minimum octane rating in the manual.<p>----------<br>Jim<br>North central Indiana

03-31-2000, 08:21 PM
All i am saying is that it is certainly higher then 87!!!!

03-31-2000, 09:52 PM
Actually all my shindaiwa equipment needs only 87 octane. According to the manuals anyways. But my echo hedgetrimmer needs 89. The shindaiwa equipment calls for a 40:1 mix, while the echo calls for 50:1. So I just use 89 octane at a 40:1 mix for everything.

Lawnforce 2
04-03-2000, 03:55 AM
on my blower i use the owners guid to do the mix , but my trimmers doesn't have a mix. it is a 4 stroke new honda trimmer. best trimmer i have ever used... runs cool to. i recomend it to people! that way you don't have to worry about mixing much gas. just mix a little for the blowers<br>