Yesterday's Tractor Co.
Shop Now View Cart
   Allis Chalmers Case Farmall IH Ford 9N,2N,8N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   Traditional YT Forum ViewClassic View   RegisterRegister 
 ProfileProfile    Log inLog in 

40:1 or 50:1 gas mix

Goto page 1, 2  Next

 
Post new topic    
View previous topic :: View next topic  
Author Message
Old560
Regular


Joined: 11 Dec 2015
Posts: 171


Report to Moderator

PostPosted: Thu Jun 14, 2018 6:10 am    Post subject: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

Does it really matter if you use 40:1 or 50:1? I?m working on a weedeater for a friend it says 40:1. All I have around here is 50:1. I?ll probably mix up some 40:1 just curious on opinions.
 
Back to top
View user's profile
kcm.MN
Tractor Guru


Joined: 20 Feb 2017
Posts: 7103
Location: NW Minnesota

Report to Moderator

PostPosted: Thu Jun 14, 2018 6:34 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

50:1 will work just fine. However, many 50:1 engines don't like being fed 40:1 mixtures. Not enough lubrication.
 
Back to top
View user's profile
docmirror
Long Time User


Joined: 22 Sep 2016
Posts: 816


Report to Moderator

PostPosted: Thu Jun 14, 2018 6:38 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

kcm.MN wrote:
(quoted from post at 07:34:18 06/14/1Cool 50:1 will work just fine. However, many 50:1 engines don't like being fed 40:1 mixtures. Not enough lubrication.


You have it backwards sir. 40:1 has more lubricating oil per volume and per weight than 50:1.

40oz fuel to 1 oz oil = 2.5% oil to fuel mixture

50oz fuel to 1 oz oil = 2% oil to fuel mixture
 
Back to top
View user's profile
Richard G.
Tractor Guru


Joined: 08 Oct 2000
Posts: 8842
Location: Oakway, SC

Report to Moderator

PostPosted: Thu Jun 14, 2018 6:44 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

I do 25 to 1 in all my 2 cycle engines. And don't notice any extra smoke either. My old friend that was a small engine repairman recommended 16 to one in everything 2 cycle.
He said engine would last much longer. Never had a problem using 25 to 1 as long as you are working the engines and not just letting sit and idle.
Richard in NW SC
 
Back to top
View user's profile
docmirror
Long Time User


Joined: 22 Sep 2016
Posts: 816


Report to Moderator

PostPosted: Thu Jun 14, 2018 6:45 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

CVPost-old560 wrote:
(quoted from post at 07:10:19 06/14/1Cool Does it really matter if you use 40:1 or 50:1? I?m working on a weedeater for a friend it says 40:1. All I have around here is 50:1. I?ll probably mix up some 40:1 just curious on opinions.


Use the 40:1 in that weedeater. Although oils have improved, and machines have become more tolerant of less oil mix, it may be an older machine that was designed for 40:1. If you use 50:1 it will work well at idle and low power but may overheat at high output.

Most of the remaining 2 stroke engines out there(except small weedeaters, blowers) use oil injection with a variable ramp mixture set by throttle. Yamaha 2 stroke jet skis set about 60:1 at idle, and gradually increase the ratio to 35:1 at full throttle where upper cylinder lubrication demands are greater. (they aren't made anymore, all 4 stroke now)

Back in the 50s, mix ratios were much higher. 2 stroke drone engines from McCulloch were 20:1. Of course the oil wasn't very good back then so they needed a lot.
 
Back to top
View user's profile
kcm.MN
Tractor Guru


Joined: 20 Feb 2017
Posts: 7103
Location: NW Minnesota

Report to Moderator

PostPosted: Thu Jun 14, 2018 7:15 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

docmirror wrote:
(quoted from post at 07:38:36 06/14/1Cool
kcm.MN wrote:
(quoted from post at 07:34:18 06/14/1Cool 50:1 will work just fine. However, many 50:1 engines don't like being fed 40:1 mixtures. Not enough lubrication.


You have it backwards sir. 40:1 has more lubricating oil per volume and per weight than 50:1.

40oz fuel to 1 oz oil = 2.5% oil to fuel mixture

50oz fuel to 1 oz oil = 2% oil to fuel mixture


Dang, you're right. ...Sure wish I could figure out which end of my brain to figure from! *lol*

Thanks Doc.
 
Back to top
View user's profile
Russ from MN
Tractor Guru


Joined: 11 Feb 2006
Posts: 7800
Location: N MN

Report to Moderator

PostPosted: Thu Jun 14, 2018 7:18 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

I only mix 43-1, that's 3 oz per gallon. My 11 engines are anywhere from new to 46 years old, they all run great and last a long time.
 
Back to top
View user's profile
Steve@Advance
Tractor Guru


Joined: 12 Nov 2013
Posts: 11422


Report to Moderator

PostPosted: Thu Jun 14, 2018 7:30 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

You want opinions, so here's mine...

I would run 50:1 premium synthetic oil. Be sure it is for air cooled engines.

I run it in everything, never had a problem. Chances are you are not running the weed wacker at full throttle and full load continuously. The max oil ratio is only needed under those conditions. Even then, if a chain saw can handle 50:1, and run full power, everything else should be a breeze!

What I have seen from running too much oil, and running cheap generic oil, it tends to carbon up the exhaust side of the piston and cylinder wall. The carbon gets in the ring land, sticks the ring, also the build up and crowds the piston over, loosing clearance to the point of having a seizure.
 
Back to top
View user's profile
dpendzic
Tractor Expert


Joined: 05 Mar 2009
Posts: 2045
Location: long island NY and Hancock Ma

Report to Moderator

PostPosted: Thu Jun 14, 2018 7:42 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

my old Johnson outboards took 16 to 1 ratio
 
Back to top
View user's profile
D beatty
Tractor Guru


Joined: 23 Jan 2013
Posts: 7594


Report to Moderator

PostPosted: Thu Jun 14, 2018 8:08 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

I have since about 1999 have use Opti-2 in every thing and one mix works in every thing. I have used it in saws and weed eaters that were over 25 years old to new machines. I have run it in McCoulloch,Husky, Homelite,Poulan, Stihl, and Echo and saws run clean no smoke and longer plug life and one mix of fuel to run them on.
 
Back to top
View user's profile
INCase
Tractor Expert


Joined: 22 Jul 2002
Posts: 1950
Location: Indiana

Report to Moderator

PostPosted: Thu Jun 14, 2018 8:14 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

the reason for the ratios is the engine manufacturers have set up what they think is the minimum oil ratio based on the cheapest, junkiest oil on the market. apparently some engines need more than others.

IF IF it is GOOD 2-stroke oil you can use the lighter 50:1 in the 40:1 engine.

AMSOIL stands behind their Saber 2-stoke oil at 100:1 in any 2-stroke engine. I've used it (dealer) in a couple of my weed-wackers with no issues.
 
Back to top
View user's profile
jeffcat
Tractor Guru


Joined: 28 Sep 2004
Posts: 11320


Report to Moderator

PostPosted: Thu Jun 14, 2018 8:15 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

Correct! 40 or 50 to one is as you say. I have some really old Mall
and Disston saws. Also Mc Culloch saws that go back to their second
model. I run everything 36/38 to one. Have several Eagle saftey cans
that I have found over the years that were purposely made with a 3/4
gallon capacity. Throw in a bottle of GOOD quality oil "major
manufacturer name" and 3/4 gallon of Hi-test gas. Everything I have
just runs clean and dandy. Those real old saws when mixed 16 to one
and were running with 40wt motor oil. Smoked like a steam locomotive.
The synthetic oils are fabulous in comparison. What needs to be
remembered.....50 to one is to meet the polution BS standards. They do
NOT care if you blow your engine after a short life. I'll take my
36/38 to one mix anyday.
 
Back to top
View user's profile
docmirror
Long Time User


Joined: 22 Sep 2016
Posts: 816


Report to Moderator

PostPosted: Thu Jun 14, 2018 8:40 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

Lots of good comments from long-time 2 stroke users here. The switch to higher ratios had a lot of things at work. Much better 2 stoke oils, change to mostly synthetic(although the base stock is really not a true syn, it is a dino base), better metalurgy for 2 stroke pistons, cyl and rings, and of course - EPA regs.

Older 2 strokes used more fuel as well, with stoichiometric ratios running as rich as 11:1, where a perfect fuel air mix is about 13.2:1. As the engine runs leaner, it also gets less lubrication. The modern oils and modern metals can handle much lower oil mixtures at leaner settings, and the older engines seem to survive ok mostly due to the higher stoich of air/fuel. The carbonizing deposits are a mix of oil, and unburned fuel. However, don't try to run an older engine leaner, or if one does, then one must increase the oil mixture to insure adequate lube of the upper cyl. A 20-30 YO saw, or other 2 stroke will NOT run well with a lean mixture of 13:1 with a 50:1 oil mix. It will overheat, it will seize(eventually).

Injection-lube in jet skis, and snowmobiles came about because engines were blowing up with a pre-mix of 50:1 as those engines are beat to death by kids who go out and run full throttle constantly. The EPA got into it as well with new regs on emissions and the mfg tried to meet the new regs. Water cooled engines have a different requirement than air cooled, but they can work pretty close.

I would(and do) feel comfy running almost anything around 40:1 pre-mix. I don't like 50:1 unless I know the engine is not going to be worked real hard, or I know I can change the stoich mixture with a screw at the carb. Most small 2 strokes no longer allow the mixture screw to be moved, but some have it, and it's covered by a plastic snap cap. The other countries allow the mixture to be set, but in the US that feature is disabled(unless one removes the plastic snap cap).

If you have a mixture screw, note that it may be for the high RPM, or it may be for low RPM. Adjust with caution and read the plug after running for less than an hour. A white, or super clean plug indicates too lean, and that will lead to damage. It should be nice and tan, or a light chocolate for best stoich.

I run some 2 stroke aviation engines, and we are super-critical on oil, mixture, stoich, and general condition of the plugs each 5-10 hours of run time. Mistakes in aviation engine running can be very costly, or painful.
 
Back to top
View user's profile
Jeff NWOH
Long Time User


Joined: 05 Mar 2009
Posts: 949


Report to Moderator

PostPosted: Thu Jun 14, 2018 9:00 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

I mix with Stihl oil 2.5 gallons at a time. It comes in the pre-measured bottles and mixes at 50:1. I use it in anything 2 stroke. Never any issues.
 
Back to top
View user's profile
David G
Tractor Guru


Joined: 11 Jan 2008
Posts: 21472


Report to Moderator

PostPosted: Thu Jun 14, 2018 11:10 am    Post subject: Re: 40:1 or 50:1 gas mix Reply to specific post Reply with quote

Me too.
 
Back to top
View user's profile
Display posts from previous:   
Post new topic    Yesterday's Tractors Forum Index -> Tractor Talk All times are GMT - 8 Hours
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  

TRACTOR PARTS TRACTOR MANUALS
Fast Shipping!  Most of our stocked parts ship within 24 hours (M-Th). Expedited shipping available, just call! Most prices for parts and manuals are below our competitors. Compare our super low shipping rates! We have the parts you need to repair your tractor. We are a company you can trust and have generous return policies. Shop Online Today or call our friendly sales staff toll free (800) 853-2651. [ About Us ]

YT Home  |  Forums

Modern View Forum powered by phpBB © 2001, 2005 phpBB Group

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters