Higher octane required in backpack blowers?

130perweek · May 5, 2009

I've been hearing of a few guys in my area that they are blowing up their backpack blowers because their gas/oil is 87 octane instead of 89 octane. Does anyone know what manufacturers and what make blowers are coming through that require the 89 octane? A few guys have been saying the Red Max is blowing due to 87, and I think, it's Husqvarna (?) that is now requiring 89 octane? Any more info on this? And who runs the 89 over the 87 and why? I know, lots of questions, but I'm thinking that this whole requirement for Plus gasoline is just another way to stick it to the landscapers. Thanks. I'm running the Dolmar backpacks (not top-of-the-line powerful, but the most reliable I have used to date), and the owners' manuals for them do not state a specific octane, just "regular gasonline" and oil mix.

-Chris

Southscapes03 · May 5, 2009

I was told by my tech guy here to always run 89 or higher in my mix gas. He said that it automatically lowers the octane rating when you mix with the oil and unless your running a lot of 2cycle gas each week it sits for a while which affects the rating as well. So, i have always used 89 in my machines with minimal problems

Pietro · May 5, 2009

My local dealer put up a sign on the front door telling us all to switch from 87 to 89. The gas got crappier thats all. Hell, my guys were using 89 in the MIX and 87 for the mowers...I told em use 89 for it all. I wont risk blowing up my hard paid equipment over a few $ in gas.

Pennington Lawncare · May 5, 2009

I looked up the manual for a PB 500 and didn't see any mention of octane. The manual does say that you should not use fuel that has been pre-mixed with 2 stroke oil if it's over a month old. Gasoline loses octane over time so the fresher the fuel the higher the octane will be. Each engine manufacturer has their own design and fuel octane requirement. I'd contact someone at Dolmar to confirm what octane fuel should be used with their equipment. It's pretty unusual for a manufacturer to not list the recommended octane. If you are worried I'd use 93 octane. Use a quality oil as well.

HighlandLC · May 5, 2009

I usually run higher octane, especially when the Summer heat arives, a bit of a safety margin for detonation and lean conditions.

THEGOLDPRO · May 5, 2009

i have always run 87 octane, we have some backback blowers that are 10+ years old as backups and they have run 87 their entire life with no problems.

Premier landscaping south · May 5, 2009

My owners manuel for BR550 says 89 octane.

kaferhaus · May 5, 2009

ALL Stihl handhelds are supposed to run on 89 octane gas.

BCarlson · May 5, 2009

Same in this part of the country, with the added ethanol in the gas (here it's 10%) started burning up small engines left and right. State law states the ethanol but after all the problems they started allowing a few companies to distribute non ethanol super unleaded for lawnmowers, small equipment and pre 1950's cars.

4curbappeal · May 5, 2009

????? Then better start puttin it in your cars and trucks!!!!!!!!!!!!!!!!!!!!!!!

Wizz · May 5, 2009

Always use 89 or higher in handhelds, Stihl also specifically states to use 89 or higher. In cars there is a misconception that higher octane is 'better' by somehow running cleaner or giving more power, which it does neither. If a car doesn't specifically specify high octane then you actually get better performance and gas mileage w/lower octane fuel. It's amazing how many people run high octane in vehicles that don't specify it thinking it somehow runs cleaner or improves performance....kinda like the people putting 100 octance race gas in a stock Corvette, won't do anything for it except hurt gas mileage.

HighlandLC · May 5, 2009

BCarlson said:
Same in this part of the country, with the added ethanol in the gas (here it's 10%) started burning up small engines left and right. State law states the ethanol but after all the problems they started allowing a few companies to distribute non ethanol super unleaded for lawnmowers, small equipment and pre 1950's cars.

You aint seen burndowns till youve seen 2 stroke sleds burning down up north in the winter. Alcohol should stay out of gas and in the Beer....:laugh:

4curbappeal said:
????? Then better start puttin it in your cars and trucks!!!!!!!!!!!!!!!!!!!!!!!

Vehicle engines ( 4 stroke motors) are very tolerant to bad gas, and you dont get the lean condition that overheats and blows the motor.

Lonny90 · May 5, 2009

Redmax is asking for 89 octane. This is due to the fact that the newer engines are running tighter tolerances and leaner mixtures due to the EPA standards. The higher the octane, the higher the detonation tolerance; newer engines with their tighter tolerances run risks of premature firing if their octane is too low.

Mowbizz · May 5, 2009

I've used 87 exclusively for 3+ years with no problems. I may be upgrading to 89 just for a little preventative peace of mind...

DLCS · May 6, 2009

I've used 87 for over 10 years and have never blown up any 2 stroke engines. I have some that are over 10 years old and still run great.

As far as ethanol, we have been using blends here in the midwest for years and no problems.

WH401 · May 6, 2009

Stihl recommends it in the BR600 manual so that's why I run it, that and the ethanol lowers the detonation point of the gas. Instead of the gas igniting from the spark plug, it's igniting from the heat on the piston and will literally blow the engine apart.

Whitey4 · May 6, 2009

I run 89 in everhthing... and am even considering going to 91 for my handhelds. When they started with the ethynol, I noticed my truck was not happy... maybe just a hunch, but I went to 89.

mowerknower · May 6, 2009

WH401 said:
Stihl recommends it in the BR600 manual so that's why I run it, that and the ethanol lowers the detonation point of the gas. Instead of the gas igniting from the spark plug, it's igniting from the heat on the piston and will literally blow the engine apart.

\
Well said, lower octane ignites easier there for causing preigntion. It hammers the crap out of the rod bearings. I really feel bad for you guys with ethonal. Thank God we dont have a lot of it here yet. Engines like dinasours not corn.

SfTD_service_CENTER · May 6, 2009

i run 110 sunoco in all small equipment with spectro full synthetic 32:1 all my stuff runs great lol just costs alot more to run it. i started doing this after i blew two robin weedwackers which were 4 stroke bh2500's it was from ethanol, out of my own gas pump, i own a gas station. i run wide open for long periods of time the race fuel seems to take all the worries away from doing that. i alos used to race motocross and that is what i ran in my bikes same mix and ratio and i ran wide open alot and never had a problem.

Pennington Lawncare · May 6, 2009

Did you have a higher compression head on your motocross bike? 32:1 is pretty unnecessary as well. Unless you are trying to kill bugs. Performance of a 2 stroke engine can actually be less when running a fuel with an octane that is higher than the compression ratio requires. There is a formula which shows which octane should be used with what compression ratio. Here's a question, which fuel is easier to ignite? 87 or 93 octane?

Higher octane required in backpack blowers?

130perweek

Southscapes03

Pietro

Pennington Lawncare

HighlandLC

THEGOLDPRO

Premier landscaping south

kaferhaus

BCarlson

4curbappeal

Wizz

HighlandLC

Lonny90

Mowbizz

DLCS

WH401

Whitey4

mowerknower

SfTD_service_CENTER

Pennington Lawncare

Top Contributors this Month

Recommended Communities