what octane gas in a 361?

[willsaw4beer]

Stihl ultra 50:1 and 93.

No reason to run anything other than that.

 

[xcr440]

Anyone else notice that when it is cold out(below 20*f) that the higher octane fuels don't seem to run as well.

I have noticed that the engines don't run as crisp on 91+ as it does with 89 and 87 octane. I have also noticed that there are other name brand 2 stroke oils that works just as well as hp.
My father in law uses one mix. I pulled the jug off his "cheapy" poulan/craftsman saw and his piston and cylinder look spotlessly clean. Nearly new. This after 10 heard years of use.

Just my findings.

 

[DougNH]

Anyone else notice that when it is cold out(below 20*f) that the higher octane fuels don't seem to run as well.

I have noticed that the engines don't run as crisp on 91+ as it does with 89 and 87 octane....
Just my findings.

This is true, but if you understand some of the chemistry involved there are relatively inexpensive ways to get around it without resorting to octane that is lower than recommended.

 

[Slamm]

I run AV in everything now, all the saws are ported and several are advanced and the saws do run better on this gas than on 93. I sent the AV gas with same Amsoil Saber mixed at 50:1 to the saw builder to have them "retuned" to the AV gas, and he said it was more noticeable on the 361 and 441, which have both been worked over. The big bore 660 didn't seem to care as much but the higher reving ported original PC 660 was better with AV and the ported and advanced 084 was better with the AV gas. He thought the ported 260 ran better with the AV gas.

All the saws after been tuned to 93 could be leaned out more with the AV than with the regular 93 gas.

All that being said, I ran my ported saws a good bit logging on nothing but regular 93 with ethonal here in Illinois without any observed failings, I think they run better now, but that doesn't mean the trees didn't fall over before, LOL.

I'm just not working as much now, and like the benefits of AV not going to heck after a month or so like auto gas does. After years of having problems with 2 stroke and small engines going to pot because of getting busy and letting them sit with crap gas in them, I have just switched everything over to the AV, the price difference isn't that big of a deal, and the benefits are knowing the engine or carb damage isn't going to take place while the thing sits for an unknown amount of time, plus when the do run, they run better.

My opinion and experience,

Sam

 

[DougNH]

I'm just not working as much now, and like the benefits of AV not going to heck after a month or so like auto gas does. After years of having problems with 2 stroke and small engines going to pot because of getting busy and letting them sit with crap gas in them, I have just switched everything over to the AV, the price difference isn't that big of a deal, and the benefits are knowing the engine or carb damage isn't going to take place while the thing sits for an unknown amount of time, plus when the do run, they run better.

My opinion and experience,

Sam

:agree2:

It's for these reasons and not "octane" that I use race fuel. Sometimes I go through 3 gals in one weekend and sometimes it takes me 6 weeks to use 1 gal. With better fuel I don't worry if a little stays in the tank of my saw until next week. I also think that most people seriously underestimate just how poor the quality of ethanol blended reformulated gasoline really is, because it works fine in your Honda Accord that gets a fresh tankful every week. If you've ever seen various carburetors ruined from being full of green-slime, phase-separated E10, holes in motorcycle fuel tanks that rusted through over the winter from being stored full of E10 that absorbed water, or the big difference in dyno numbers between E10 and pure gasoline, you would probably feel the same way. The sad thing is that what used to come straight out of the pump not too many years ago was much more similar to the race fuel and avgas that we're now paying $3.50 to $10 a gallon to buy.

 

[Slamm]

Yeah, I was paying 6-7 dollars for Race Gas, but the airport has AV 100 octane for 3.50 or less and that's not bad, we were paying more than that last summer for regular crap, LOL.

With the money I have in my saws and other small motors, I really like the benefit of quality gas not going to crap and causing engine or carb damage/problems that really ruin a weekend or emergency opportunity to use my saws, just because they had to sit for awhile. Not to mention they run better when I do use them.

Since you can't just get the AV everywhere it does take a little more brain power to prepare for future needs, so I get plenty and have plenty stored, but again, I can do this because it stores longer.

Sam

 

[Banshee]

Good lord, they are going to arrest you! FYI, 100LL is a euphemism, it has about 10 times the lead that regular leaded gasoline used to have.

Not a good idea, runs fine now, but it will plug up with those lead deposits, not to mention bad for you (pretty much directly injecting the stuff) and environmentally its ugly.

Just run as a high an octane premium as you can get and it will run good for a long time.

Actually 100ll(100 low lead) has around 2 grams of lead vs 2.5 grams for leaded. High test is just a tad over 4.2 grams.

With the lack of lead in unleaded it will build up varnish and deposits much faster than leaded gas. Unleaded won't tolerate high-compression engines as well, stores poorly and reacts poorly to the presence of oil, as in a two-stroke pre- mix situation.

 

[cherrycutter]

smoker, the only way lead deposits will form is if you have a crappy spark plug or dont have a hot enough ignition source. I just pulled the plug on my 441 after about 5 gallons of av gas with stihl ultra and it's just nice and brown. Piston looks brand new. I don't cut on state or federal property so im not going to get into trouble for using it. I am an ER nurse and know quite well that lead is toxic but like banshee said this gas has less lead than the leaded gas of before and im not exactly sucking on the muffler port.