89 octane in B&S engine?

[fred9xx]

I just bought a Snapper RP21875 with a B&S 8.75 engine.
I'm posting to pass along and ask about the dealer saying to use 89 octane gasoline. He says it will run smoother.

Do you agree?

(He is the owner and along time small engine mechanic.)

 

[Donald]

OK, so we assume he has done no scientific testing. What does the manual say?

In most cases using gas with more octane than is called for is a waste.

BTW most marine engines are timed to run on 89, which is what most marinas sell.

Having said that I have a 22" Airens mulching mower that when the grass is a little tall or thick bogs down and almost stalls. When its in this almost stall state, it makes some noises that sound almost like knocking. So I wonder if that was what he was talking about.

 

[eljefino]

Back in the day regular leaded was 89. IIRC that's why midgrade unleaded stuck around, to fuel older cars.

I bet 99% of your gas stations blend regular and super at the pump, so you aren't finding any magic elixir.

My briggses run the same on any fresh clean gas. In fact they even like coleman fuel (white gas) with an octane in the 60s-70s!

 

[Quest]

IMHO Octane rating of 87 (RON+MON divide by 2) is pretty much norm for flat head B&S, no need to run anything higher than 87 for it's such an ancient, low compression design (pre-dates back to the Ford Model-Tee days) than you not gonna get anything close to automobile engines in terms of performance.

All the associated popping, running lean/rich, etc. has to do with carbs on those engines, and relatively little to do with gasoline octane ratings (remember: octane is about how well the gasoline resists pre-ignition during compression stroke, before the mixture hits the spark).

I'd be more worried about quality (freshness) of fuel in your case as poor quality fuel tends to carbon up the piston rings and tops fairly quickly, causing all sorts of troubles down the road.

Good luck.

Q.

(*My oldest B&S was on a 1965 tiller that still runs on original carb and tank, and points too!, just with regular 87 octane pump gas)

 

[johnachak]

I always use 89 in my small engines. We have 10% ethanol here. Even with stabilizer ethanol loses octane rather quickly. How quickly? It depends on what you read. I figure for $0.40 per 2 gallons, I have a hedge against dropping octane over the season.

 

[mechjames]

Here you gotta use 91 from shell or 94 from chevron, only two fuels you can get without ethanol, otherwise they don't run properly and gum up the carb after a few months on regular

 

[Donald]

Originally Posted By: mechjames
Here you gotta use 91 from shell or 94 from chevron, only two fuels you can get without ethanol, otherwise they don't run properly and gum up the carb after a few months on regular


94 from Chevron?? Are you sure you do not mean Sunoco? How do you know they do not have ethanol? Some states do not require a sticker on the pump for E10.

Here is the list state by state. But you are in Canada.

http://www.fuel-testers.com/state_guide_ethanol_laws.html

 

[TFB1]

Originally Posted By: mechjames
Here you gotta use 91 from shell or 94 from chevron, only two fuels you can get without ethanol, otherwise they don't run properly and gum up the carb after a few months on regular


I've used E-10 87 in my mowers without issue, the blend(s) has been the only fuel we can get for probably five years now...

I have a derelict '88 Turbo Coupe T-Bird that sets behind my garage that I move every month or two to cut grass and clean up the area... It gets maybe two gallons of gas added per year... Throw a battery in it, she'll fire up and run just like it was started yesterday... I had another that was stored inside and the fuel pump gummed up, but that one wasn't started for close to two years...

 

[southernjeeper]

down here there are stickers on the pumps that say "contains 10% ethanol" or others now stupidly switching to "contains 15% ethanol"

But I have found there are less than 5 gas stations around here that sell just straight pure gasoline, which is great! Though their price may be a little higher, but who gives a darn when that keeps your mpgs and power to your car or truck better! Ethanol is just to make gas prices drop not necessarily helping too much...

that's my 2cents about the subject

 

[Cujet]

Same here. Super 93 runs better. I have idle problems with E-10 gas. But the local super has none, or much less ethanol.

Regular was around 4-5% in the past year, but now it up to near 10% Ethanol.

 

[odie]

Use 93 octane for all the mowers and the snowblower . No issues yet .

 

[Turk]

I use 91-93 Non-Oxy Gas in all of my small engines uncluding the B&S ones, every time, for the past 30 years. ...and I use them a lot with 3 acres & a 180' driveway!

- Not one single gas/engine problem.

- Not one single leak.

- Not one single carb or engine rebuild.

It works and works great. Try to fault that. Anyone.

 

[Racerjk]

I'm running Non-ethanol 92 or 93 octane in everything I own from cars down to weedeaters. No trouble at all. The Kohler on my Craftsman loves the ethanol free gas! I can 3 mowings per tank versus only 2 with E10 gasoline.

 

[raffy]

As I've said on other threads, Mayberry's recommends using 89 octane or greater gas on all the OPE they sell. I bought a Honda generator from them and that was their recommendation as they said the fuel would store better and make the genny run better, apparently because of the lower ethanol content.

I've decided I will be using 89 octane or higher gas on all my OPE from now on, and I will make an effort to get such gas without any ethanol. I have already purchased almost 5 gallons of 89 octane pure gas for next season and emergency use and have treated it with stabilizer. There are several gas stations in my vicinity that sell no or low ethanol gasoline. Here in the state of Alabama, the law mandates that gas pumps have a clearly visible sticker indicating the presence of more than 1% ethanol in gasoline. No sticker on the pump means essentially (or at most 1% ethanol) pure gas.

Interesting about the fuel consumption there, Racerjk. I know that 10% ethanol fuel has less heat content but didn't think it would make that much difference!

Here's the link to Mayberry's recommendation:

http://mayberrys.com/faq.htm

 

[Letter_K]

I do have to laugh at all the comments like "I've used non-ethanol" gas for XX years and mine runs great."

I'm quite the contrary. I live in Minnesota and almost all regular gas, except for that rare station with racing gas has had ethanol for at least 10 years. Contrary to popular and misguided belief I still have working cars and small engines. That even considers that many of it gets stored wet for the winter. According to many of you , I should be on my 5th lawnmower in the last 8 years.

I have a feeling this is what it was like in England when people resisted fluoride in the water.

 

[Spazdog]

Echo recommends 89. Rather than swipe my card a bunch of different times for a bunch of different octanes, I just fill up my gas cans with 89 now.


....and running the Troy-bilt string trimmer on 89 with Echo 50:1 instead of the recommended pre-mix. That fool thing is running better than it ever did on 40:1 + 87 octane. I thought for sure that and extended operation in 110° weather with a thinner mix would kill it and I would have a good excuse to go buy a matching Echo string trimmer but it's running really good.

 

[Turk]

Originally Posted By: Letter_K
I do have to laugh at all the comments like "I've used non-ethanol" gas for XX years and mine runs great."

I'm quite the contrary. I live in Minnesota and almost all regular gas, except for that rare station with racing gas has had ethanol for at least 10 years. Contrary to popular and misguided belief I still have working cars and small engines. That even considers that many of it gets stored wet for the winter. According to many of you , I should be on my 5th lawnmower in the last 8 years.

I have a feeling this is what it was like in England when people resisted fluoride in the water.


Well, I'm in Minnesota also and what I've stated above is the truth. NO Issues! Perhaps you're running into other factors for your issues...

BTW: You're wrong. There are MANY gas stations in MN that have Non-Oxy Gas that's not racing gas - here's the list, along with Octane levels, to prove it:

http://pure-gas.org/index.jsp?stateprov=MN

 

[Pop_Rivit]

Originally Posted By: tpitcher
Originally Posted By: Letter_K
I do have to laugh at all the comments like "I've used non-ethanol" gas for XX years and mine runs great."

I'm quite the contrary. I live in Minnesota and almost all regular gas, except for that rare station with racing gas has had ethanol for at least 10 years. Contrary to popular and misguided belief I still have working cars and small engines. That even considers that many of it gets stored wet for the winter. According to many of you , I should be on my 5th lawnmower in the last 8 years.

I have a feeling this is what it was like in England when people resisted fluoride in the water.


Well, I'm in Minnesota also and what I've stated above is the truth. NO Issues! Perhaps you're running into other factors for your issues...

BTW: You're wrong. There are MANY gas stations in MN that have Non-Oxy Gas that's not racing gas - here's the list, along with Octane levels, to prove it:

http://pure-gas.org/index.jsp?stateprov=MN



Well, I'm in Iowa and I've been running 10% ethanol in everything for 30 years or more, and I too have no issues. Wait, let me get this emphasis right...NO Issues!

That includes my tiller that gets run once a year, my 1960's vintage David Bradley chain saw that gets run once or twice a year, my 1975 John Deere 210, my 4 Ford N tractors, one of which only gets run once or twice a year when I take it to shows and one that only gets run in the winter to plow my 200+ driveway, my John Deere 757 mower, and a handful of other small engines all of which get stored with fuel in them.

And, like Letter_K, I get a chuckle out of the people who think ethanol is the cause of all their ills.

 

[Turk]

Man, you guys get polar!

I'm sure if I ran 10% Corn I'd be ok too, just like you.

My original post was to rest the concern the OP about running 89 Octane.

Heck, I could have left off the Non-Oxy typing, I was just giving more information and this happens? Geez you guys.

I was letting him know:

- What I ran

- For how long

- What was the result

Run all the Corn you want, I don't care. I'll run what I want too.

Oh, LetterK is still wrong about his claim against me.

 

[odie]

Forgot to mention it's VALERO 93 w/ E10 . So far , so good .