71:1 Ratio Fuel Mix

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Trigger-Time

Trigger-Time

Addicted to ArboristSite
Joined
Sep 20, 2006
Messages
4,717
Location
U.S.A. :)
71:1 Ratio, thats the Ratio for this pre mix.
Anyone here tried it?

attachment.php
 
Trigger-Time

Trigger-Time

Addicted to ArboristSite
Joined
Sep 20, 2006
Messages
4,717
Location
U.S.A. :)
IMO......and just, IMO oil are soooo much better today and the Synthetic
oils are even better. I have hinted about running a saw at 60:1 or 70:1
to see how long it will last........again IMO, with the oil today I don't think
60:1 will hurt a thing with Synthetic.....am I going to gamble my $900
MS660 on 60:1......you can bet your a$$ I'm NOT! I just think the oils
will do better than they are telling us. IMO 50:1 is not the edge of the
mix, they have a safety margin, I would think.

Oregon, is saying that there oil will do a lot better than 50 to 1
 
troutfisher

troutfisher

Addicted to ArboristSite
Joined
Jan 4, 2007
Messages
1,775
Location
Fishin' the Adirondacks
IMO......and just, IMO oil are soooo much better today and the Synthetic
oils are even better. I have hinted about running a saw at 60:1 or 70:1
to see how long it will last........again IMO, with the oil today I don't think
60:1 will hurt a thing with Synthetic.....am I going to gamble my $900
MS660 on 60:1......you can bet your a$$ I'm NOT! I just think the oils
will do better than they are telling us. IMO 50:1 is not the edge of the
mix, they have a safety margin, I would think.

Oregon, is saying that there oil will do a lot better than 50 to 1

Ya know, If I could step back in time and tell someone running a saw in 1955 that I mix gas at 50:1, they'd laugh at me. It seems that over time we are mixing less and less oil. first 20:1, then 32:1, then 40 or 50:1, the trend continues.......
 
Trigger-Time

Trigger-Time

Addicted to ArboristSite
Joined
Sep 20, 2006
Messages
4,717
Location
U.S.A. :)
Ya know, If I could step back in time and tell someone running a saw in 1955 that I mix gas at 50:1, they'd laugh at me. It seems that over time we are mixing less and less oil. first 20:1, then 32:1, then 40 or 50:1, the trend continues.......

Very true.........I'm now going OT In 1989 I started changing
the oil in my pickup every 12,000 to 15,000 miles. Sold it to dad with
over 200,000 miles on it.....its just a farm truck now.....motor wise
I put one timing chain in it.....it still dose not smoke, will use 1/2 quart
of oil in 15,000 miles (Dino oil)........bought a new pickup in 2005, I'm
now using a blend, went 500 miles first oil change, now ever 15,000 miles
Oil is SOOOO much better IMO
 
Trigger-Time

Trigger-Time

Addicted to ArboristSite
Joined
Sep 20, 2006
Messages
4,717
Location
U.S.A. :)
I think another reason they are staying with the 50:1 on
the Synthetic, afraid people will mix dino oil to what ever ratio
the Synthetic oil called for.........but like the little Oregon 1 gallon
mix, dose not tell the ratio.......just mix pack with 1 gallon of gas.
I would say 95% of the people will not try to figure the ratio.
(and most don't know how)
 
glenn31792

glenn31792

ArboristSite Guru
Joined
Apr 1, 2007
Messages
527
Location
so,ga
I have a lot more 2 stroke motorcycle experience than I have of chain saw experience.
I have a different understanding than some of the posts here.
Some people speak of rich lean as the mix ratio of the oil and gas.
To me rich/ lean has to do with the jetting (air/fuel)
Going from 50:1 to 40:1 leans the motor out. Less gas more oil – they burn different.
More oil might provide extra lube but oil burns hotter ( may cause a problem).

My last big 2 stroke (bs 89x79) ran fine on amsoil synth at 88:1. I know the bottle said
100:1 but with that big of a piston I wanted a bit more oil to protect the cylinder from
Rocking forces. I spent some time to properly jet the carb in for this ratio.
Ring and piston looked fine at the end of the season but got changed anyway.

My motor with a 79 mm stroke , at 7500 rpm the piston speed in feet per min was 3887.
A 65cc chain saw turning 12000 rpm has a piston speed in feet per minute of about
3220 (assuming a stroke of 41 mm).
 
Last edited:

Latest posts

Top