what octane gas in a 361?

[johnnylabguy]

Alright, I'm new so maybe I'm an idiot but is it ok to just run regular old 87 octane in my saws? Does it make that much difference to run 91 or higher octane? If its not noticable or hard on the saw I'd like to stick with "regular" so I can run all my equipment from the same tank(before I premix the saw gas!) Thanks for the input...

 

[Bowtie]

Stihl recommends 91 or higher octane. The reason for that is these saw engines are higher compression ratio, and higher performance engines than your lawnmower and truck. Sure 87 will make your saw run, but I wont use it in my 2 stroke equipment.

 

[Evanrude]

Yep, I've always ran 91+ in her, you mights well too! :biggrinbounce2:

 

[Bowtie]

Aww crap. Stihl recommends 89+ octane. I run 91 myself, but a correction to my last post.

 

[johnnylabguy]

Hey 'rude! Good to know! Thanks for the "heads up" guys!

Does that mean I've been misfeeding my 290 for the last 6 months? (Gulp!)

 

[rngrchad]

Does that mean I've been misfeeding my 290 for the last 6 months? (Gulp!)

no.

 

[Adam in VA]

I run nothing but non-ethanol 93 octane in all my 2 cycles

 

[rngrchad]

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[Smokerr]

MS290 is a bit of an older design saw, so its likely fine (lesss picky and hot rodded back then).

Always best to follow the mfg recommends.

The 290 can take some absue, so you abused it a bit maybe, but not anywhere near the end of the world.

You really wood (pun) need to be moving up use wise a lot to need a 361. Great saw, but serious one for heavy cutting many days a week.

I am running a MS270, 10 cords a year. Not 5 days a week cutting, but when I do cut, its 3-5 hours of pretty steady cutting. Its doing great. I figure 30 cords so far and its running better all the time. One guy reports about 70 and going strong.

So unless you really have the heavy use, stick with the 290 and enjoy i for another 10 years.

 

[Bowtie]

MS290 is a bit of an older design saw, so its likely fine (lesss picky and hot rodded back then).

Always best to follow the mfg recommends.

The 290 can take some absue, so you abused it a bit maybe, but not anywhere near the end of the world.

You really wood (pun) need to be moving up use wise a lot to need a 361. Great saw, but serious one for heavy cutting many days a week.

I am running a MS270, 10 cords a year. Not 5 days a week cutting, but when I do cut, its 3-5 hours of pretty steady cutting. Its doing great. I figure 30 cords so far and its running better all the time. One guy reports about 70 and going strong.

So unless you really have the heavy use, stick with the 290 and enjoy i for another 10 years.

Stihl recommends using 89 octane or higher in that saw as well. (029/MS290)

 

[fubar2]

I didnt think them bad boys ran on anything less than rocket fuel.

 

[Banshee]

The higher the compression the higher the temp. Most saws run fairly high compression.
High octane burns cooler. Is also more resistant to premature ignition. Higher octane is also more resistant to vapor locking.

Also remember that your mix oil will lower the octane. 50 to 1 will lower you octane 2 percent so that 87 octane mixed 50 to 1 will be 85.3 octane. At 32 to 1 the mix will lowered by 3.1 percent or 84.3 octane.

So the higher octane will help your saw run cooler. Prevent premature ignition and vapor locking.

You may not have these problems, but the extra dime you spend on a gallon of 89 octane not worth it to ensure that it's not a problem in the future?

 

[cherrycutter]

I run 100LL av gas in my saws. Mine run fine on it. I have been told though that 93 octane pump gas will make more HP. I have not noticed this though.

 

[CentaurG2]

From what I here on this site, the ms361 runs on a lot hot air. Regrettably, mine refuses the hot air and runs on a “secret” mix of custom blended fuels available only in the northeast. Its 93 octane gas with stihl ultra mixed 50:1. The nice people at the pump ad a little ethanol to boost up the octane level and keep every thing squeeky clean but don’t tell anyone. It is a secret!

 

[Banshee]

I run 100LL av gas in my saws. Mine run fine on it. I have been told though that 93 octane pump gas will make more HP. I have not noticed this though.

The reason pump gas will make more hp than av fuel is av fuel has the lack of heavy burners.

Heavy burners burn longer than light burners and give more of a "push" than light burners.

You can do a mixture of av fuel and pump gas and give you the best of both worlds or worst of both worlds depending on how you look at it.

I also run av fuel and haven't notice any differance in hp.

 

[056kid]

Dont bother with higher than pump gas untill you hit 13:1 or 13.2:1 then somthing like 100 will do you good.


i took the base gasket in my 372 and it is happy with 87...

 

[xcr440]

I use anything from 87-93. Depends on what I have at the house. I really try to use 91-93 when the temps are above 70*F. When I am sawing below30*f I will use 87. It seems to run good on that octane around those temps.

I see no real need to run av fuel unless you are highly modded, which I am not.

 

[Smokerr]

I run 100LL av gas in my saws. Mine run fine on it. I have been told though that 93 octane pump gas will make more HP. I have not noticed this though.

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.

 

[blly8325]

93 octane

When I bought my Husky 371XP back in 99 the dealer specifically said "Run 93octane in your saw, it will run cooler which is better for your saw" Done that since and it runs great. Oh by the way never trust any ones mix, if you run dry. Did that (once) never again my father I.L.'s mix killed my saw. Had to rebuild it.

 

[BryanSchamber]

Started running my new 361 out on 87 because I just mixed a new 2 gal. can up. Since that can was gone I've switched to 93 and I can tell a big difference. Just my opinion anyway for what it's worth. Stihl ultra 50:1 and 93 you won't be dissapointed.