Gas/Oil Ratio

[RobertN]

I have used Premium gas with high quality mix since the first dirt bike engine I had rebuilt.

The guy that built it, built race motors for some of the Pro's; he rode with and built motors for Danny "Mr Magoo" chandler back in the day. He helped me(actually, I helped him...) rebuild a motor. He was pretty specific to use premium gas. And, use the premium oils at that time. He said the effects of oil breakdown even in good oils was noticable for racers, and engine builders, after as little as 24 hours; more engine problems, less power, that would mean 2nd place instead of 1st. Granted I was just a trail rider, but a 5 gallon can of gas only cost a little more for Premium...

We have a friend who is a pro arborist, a real tree doctor. Guy is awesome not only at trimming, but at diagnosing and saving trees. His take, is these saws are little 10,000+rpm motors. Basically little race motors. Premium gas, and good oil in conjunction with proper tuning are worth it, especially when you are 50' up in a tree.

So, I have gone by what the Pro's that I know say. It made sense to me.

just curious why you are using 93 octane?

higher the octane.. the harder it is to ignite the mix. IMHO.. on small engines.. lower octane is easier to start.. may leave less intake deposits .. also.. oil addition to the fuel increases the octane on it's own..

just saying. i'm sure it won't hurt..

 

[Soundguy]

for the guy saying read my manuals.. how about re-reading my post.

I didn't state 87 octane. I just said lower.

most palces offer at least 3 grades. ( I know of a few that offer 4-5 )

usually.. some combination of 87, 89 91 -92-93 and the occasional 100-104 stuff.

89 is lower than 93.. but higher than 87. my 15yr old mower says 86 is fine..

For the guy saying run the low octane. Read your manuals.

Stihl husky state 89 min and 89+, Solo 91 min, Dolmar dealer has a sign that says 89 min.

Running 87 in your stuff will created them to run hotter then need be.

Per Madsen's Octane Rating

The octane rating of a fuel relates to its ability to resist knocking. Knocking is the sound of the air/fuel mixture "exploding" inside a engine. Most everyone has run low grade gasoline in their car or truck at one time or another and heard a rattling sound come from under the hood. This knocking robs power from the engine and causes moments of extreme pressure on its internal components. It can also cause heat to build up. The same thing can happen to a pro saw engine, but you aren't likely to hear it knock. Cutting noise masks the sound of detonation. If you are running low octane fuel, you may not realize what is occurring until it is too late.

 

[Soundguy]

we are compairing a weed eater and a hi performance custom built race engine? a lil apples to plums comparison isn't it????

sorry.. I thought i was posting in a different thread! I thought we were talking common air cooled small lawn maint things you buy at supermart.

not special fuel dragster lawnmangler terraine eater..

i'm not sure you can draw a direct conclusion about building a custom race engine and fueling a weed eater...? except they are both internal combustion...

I have used Premium gas with high quality mix since the first dirt bike engine I had rebuilt.

The guy that built it, built race motors for some of the Pro's; he rode with and built motors for Danny "Mr Magoo" chandler back in the day. He helped me(actually, I helped him...) rebuild a motor. He was pretty specific to use premium gas. And, use the premium oils at that time. He said the effects of oil breakdown even in good oils was noticable for racers, and engine builders, after as little as 24 hours; more engine problems, less power, that would mean 2nd place instead of 1st. Granted I was just a trail rider, but a 5 gallon can of gas only cost a little more for Premium...

We have a friend who is a pro arborist, a real tree doctor. Guy is awesome not only at trimming, but at diagnosing and saving trees. His take, is these saws are little 10,000+rpm motors. Basically little race motors. Premium gas, and good oil in conjunction with proper tuning are worth it, especially when you are 50' up in a tree.

So, I have gone by what the Pro's that I know say. It made sense to me.

 

[newbury]

sorry.. I thought i was posting in a different thread! I thought we were talking common air cooled small lawn maint things you buy at supermart.

Yup, wrong thread. This was:

I just bought my first gas chainsaw does anybody know the gas/oil ratio I need to use?

So he was probably talking about a new chainsaw that runs at 10,000 RPM or more at WOT. Reads like a small racing motor to me.

 

[Soundguy]

i'll have to check my poulan manual.... I don't recall it telling me I needed racing gas..

 

[Soundguy]

ok.. my poulan reccomends 87 octane minimum.. and up to 10% ethanol is fine.. but no e85

and here is a link to brigs fuel requiremnts pdf.. says about the same. 87 / 10% e ok.

http://www4.briggsandstratton.com/miscpdfs/RNT/fuel_requirements.pdf

I knew I wasn't crazy.... you guys must have the hi-test yard maintenance machines.. the racing hedge trimemrs..

 

[Soundguy]

So he was probably talking about a new chainsaw that runs at 10,000 RPM or more at WOT. Reads like a small racing motor to me.

not me. seems like regular lawn maint item.... I looked in my poulan manual and found a BS link online. 87 seems to be common fare.. must be some spendy racing lawn mowers out there..

 

[murphy1244]

Echo says 89 octane and may contain10% ethanol.

 

[xyz123]

Now soundguy nobody was talking about briggs motors and lawn mowers.

Yes todays poulan trimmers and chainsaws say 87. We were talking husqvarna, stihl, dolmar chainsaws etc and not B&S lawn mower motors LOL.

YES I run 87 in my lawn mowers push and riders. Totally different engines and requirements.

 

[LD1]

I run 87 in my lawn mower, power washer, log-splitter, 4-wheeler, etc. But not the saws. The reccomend higher, are high compression (mine more-so than normal) and scream 13-14k. 93 octane with no ethanol for me please:thumbsup: