Need help?

Search OutdoorKing by entering Key Words Below

Who's Online Now
3 members (MowingManiac, Celts88, NormK), 273 guests, and 65 robots.
Key: Admin, Global Mod, Mod
Online Spare Parts

Online Store

Newest Topics
Husqvarna Rancher 50 Oil Vent
by MowingManiac - 18/05/24 11:23 AM
Two hardly used chains for Ozito 18 volt chainsaw.
by MowingManiac - 07/05/24 06:50 PM
Honda GX160 only runs for a few seconds
by MowingManiac - 04/05/24 05:33 PM
Victa 24 F/C crank pulleys
by NormK - 02/05/24 04:56 PM
Rover Easypush lower handle arm rhs
by Wram - 26/04/24 07:28 PM
airbox to suit b&s 193707 bne
by Wram - 25/04/24 06:54 PM
Topic Replies
Husqvarna Rancher 50 Oil Vent
by maxwestern - 23/05/24 01:00 AM
Victa: The Triplets
by maxwestern - 16/05/24 09:58 AM
Honda GX160 only runs for a few seconds
by MowingManiac - 11/05/24 07:22 AM
Ogden power push mower
by maxwestern - 08/05/24 08:11 PM
Two hardly used chains for Ozito 18 volt chainsaw.
by MowingManiac - 07/05/24 06:50 PM
Victa Imperial Project
by NormK - 07/05/24 06:17 PM
Rover Easypush lower handle arm rhs
by Wram - 06/05/24 08:15 PM
Victa 24 F/C crank pulleys
by NormK - 03/05/24 04:59 PM
airbox to suit b&s 193707 bne
by Bruce - 27/04/24 11:31 AM
Previous Thread
Next Thread
Print Thread
Rate Thread
Hop To
Joined: Feb 2006
Posts: 4,675
Likes: 164
I was reading through comments on a YouTube video on a late model Victa 2 stroke mower and some were saying they use 50:1 instead of 25:1 as long as it's semi synthetic, full synthetic or good quality oil.
A Lawn Boy 2 stroke owner in America claimed he was using much leaner mixtures with his 16:1 specified mower for years without problems.

Is it a risk of overheating or engine damage in harsh mowing environments?

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!
Membership information
Joined: Jan 2015
Posts: 1,487
Likes: 23
AVB Offline
Personally I sell a Pro Multi mix oil which is synthetic that is spec for engines running 50:1 to 16:1 fuel mixes. I haven't seen anything coming into my shop that uses 16:1 in the last 12 yrs but I have old Homelite chainsaws in my customer that uses this fuel oil mix without problems. That is a lot better than when I ran these saws as a teenager. I lost numerous PNCs using the older 25:1 fuel oil mix ratio. I got expensive cutting firewood for a living as several time during the season I was having to rebuild my saws.

Joined: Jan 2020
Posts: 171
Likes: 5
Apprentice level 2
Id be interested to get folks opinions on this as well. I've a 550 Pro that I still use for the steeper parts of my property - oil says 50:1, Victa says 25:1 - I've kinda camped in between most times

I combined a full synthetic with a mineral 2 stroke as I heard both of them have their pros and cons - but assuming your oil is decent and the Victa's are modernish - unsure if there's a best practice? But welcome seeing what others think/do.

Joined: Jul 2018
Posts: 2,086
Likes: 80
Will preface this with an apology for the long spiel

I am far from an expert, but I do have more than a passing interest in oils

A few years ago, I read the original document from a conference back in the mid 70s, when a group of engineers, (surrounded by a careless API system with ATP TC loose classification of 2 stroke oils) put a proposal forward for standardized measure of 2 stroke oils, including the engines utilised to test them - one being a honda bike engine, the other being a small Suzuki generator engine.

This plan ended up becoming the JASO ratings measure. It was well into the 80s by the time this occurred from memory.

There are 4 JASO ratings:
FA - probably you could now say oils in this grade are FA - F***ing Awful - they are the base level .
The sole FA rated oil left on the market is Shell Greenskeeper

FB - better lubricity, a bit lower smoke, less carbon.
Oil like Penrite Greenskeeper, Castrol Garden 2t, generally mineral oils

FC - much lower smoke, lower carbon, better detergency to keep engines clean
Most semi syn oils - penrite Hi-per, Castrol Activ, most of your lawn oils sold by bunnings, GA spares, Jakmax, etc. VICTA 50:1 2 stroke oil is JASO FC

FD came out in the early 00's - same as FC but better detergents.
So it is practically ashless, great lubricity, no buildup of carbon, and can help to (in theory) scrub carbon out.

Mostly are full syn oils - Penrite MC2st ester, Castrol TTS/Power1, Stihl oil (ultra) and husqvarna (LS+ is semi syn)

Putting aside smoke and carbon for a minute, the basic need for lubrication is the primary need on many of the engines we are using. Ball/needle roller bearings are great from reducing oil requirement. All Victas post 1976 have them on big and little ends and mains.

BUT pre 76 models use at least sintered brass little ends (up at the gudgeon). A bush needs more oil than a roller bearing.

Who is to say what a lot of these little 25cc chinese line trimmers have in them (most are needle bearing but probably pretty poor quality high friction ones)

Then there is film strength - we are asking a tiny bit of oil to go through a motor, lubricate (by my count) about 5 bearings on a FC engine, then get in/around piston rings, around the gudgeon, lubricate the cylinder walls, and still have a bit left to lubricate the exhaust side of the cylinder after ignition.

There are engines out there which are very prone to clagging up the exhaust spark arrester (echo especially).
Stihl Ultra oil is also bad for this when you don't run them flat stick.

There are engines that are easy on oil, and ones that are hard on oil. If its tuned properly and is smoking hot, use less oil.
No amount of tuning will get my Husqvarna 125bv leaf blower to run well on 25 as it does on 40.

Margin of error is another point - I know for a fact when i squeeze the penrite bottle up to the graduated line in the little top measurer part that when tipped, only about 90% of it will come out. No problem for me as I use a mixing bottle, but if you are squeezing then tipping 20ml into a 1l bottle of fuel without checking, your 2% mix (50:1) is now 1.8%
On 25:1, your 40ml is becoming a 3.6%

I have seen enough of stupid marketing decisions to just err on the side of caution. I have an ozito earth tiller that says 40:1, but the previous model (same engine different colour) said 25:1. Same with my GMC chainsaw saying 25 and my identical ozito saying 40.

I have a armful of old ryobi Ryan IDC motors - half say 25, 1 says 32, one says 35, one says 40 and another says 50. I have seen an earlier one say 20:1

The engine stayed the same (mostly - aside a stupid compression release), marketing decided that as long as they don't cark it too quick, low smoke is a benefit.

I use Penrite MC2st Full synthetic FD. Its about $22 on special for 1l - I use between 1 and 2l per year. I run near what the manufacturer says - except 16:1 - that is from a time when the oils were so poor that the exhaust side would be fried - or 50:1.

I mix 3 bottles of fuel - 25:1, 40:1 (which is actually 35:1) and 50:1 (which is actually 40:1)

I often will get a decent puff of smoke on start up (from victas on 25:1), but none when running in any of them.

Cannot recall a properly carboned up plug - they all come out pretty clean. My technique for running is exactly what everyone says not to go - I rarely use full throttle on hand helds and only full throttle on mowers about 1/4 of the time

I did kill a plug last year on a victa powertorque. Was scalping the hell out of the lawn. a few weeks prior I tried doing it with a 190cc quantum and it had a coronary and couldn't do what I wanted.

I put about 2 tanks through it and got about 25+ catchers off of only an 80sqm area. Full throttle the whole way at low height of cut.

Towards the end it started backfiring up the snorkel and died. Was worried I had cooked the motor as the plug a tad dry, but with a new plug it finished off fine, and a piston inspection through the exhaust port revealed no change (aside from a lot of carbon being burnt out). that was on 25:1 - 50:1 might have seen a different ending.

2 members like this: N1KK0, Mowerfreak
Joined: Nov 2013
Posts: 6,938
Likes: 278
Forum Historian
G'day all oil lovers
In the 'old days' 2-stroke oil was named 'petroil'.
Typically, the oil was regular engine oil added to petrol.

The advent of sophisticated synthetic oils seems to have
changed everything.

I had a Victa Razor that had an 'Ecotorque' engine.
I never had any problem with the recommended 50:1 mix.

I also note that the Victa Imperial had recommended 80:1 mix.

I really enjoyed Tyler's expertise and take on this.
It's a topic I'm well out of depth on, so thanks to all.


Joined: Feb 2006
Posts: 4,675
Likes: 164
Hi all.

The blue Aldi synthetic two stroke has no standards it meets written in the bottle, but my side pull full crank from the early 80s blows no smoke with 25:1 mix with the stuff.

It's probably cleaning it out every time I use it.

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!
Joined: Feb 2006
Posts: 4,675
Likes: 164
Speaking of, look what's baaack!
Still $12.99.

Attached Images
IMG_20210921_185801_copy_564x1000.jpg (53.66 KB, 53 downloads)

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!
Joined: Dec 2010
Posts: 34
i reckon over the years my pt has copped everything from 50;1 to left over 16:1 castor racing fuel left over from the go kart when i was racing, nothing seemed to worry it, at the end of the day they are a fairly low rpm low stress motor

Last edited by billyj; 22/09/21 12:03 PM.
Joined: Oct 2020
Posts: 49
Likes: 8
Go the Powertorque engine!
The relative simplicity, ease of doing repairs and maintenance, durability, ruggedness, and seemingly endless willingness to never give up, even on the thickest of weeds, shrubs, vines, stems -and even small trees makes them appear at the top of any list of contenders for “ best small engine” for push mowers, in my opinion.
There just doesn’t seem to be too many issues or significant drawbacks that appear on a regular basis, with these engines.

Moderated by  bigted, Bruce, CyberJack, Gadge, Mr Davis 

Link Copied to Clipboard
Newest Members
joat, chrispford, leventis, DallasOnesto, dallasf
16,799 Registered Users
Forum Statistics
Most Online2,545
Dec 23rd, 2019
OutdoorKing Showcase
20 Bucks from FB Marketplace
20 Bucks from FB Marketplace
by Return Rider, February 20
Victa Cortina 2 Shed Find
Victa Cortina 2 Shed Find
by Return Rider, January 25
My Rover Baron 45
My Rover Baron 45
by Maxwell_Rover_Baron, April 16
SHOWCASE - Precision Mowers - 2021
SHOWCASE - Precision Mowers - 2021
by CyberJack, April 14
SHOWCASE – Atco Rotary – Paul C - 2020
SHOWCASE – Atco Rotary – Paul C - 2020
by CyberJack, December 28
Powered by UBB.threads™ PHP Forum Software 7.7.5
(Release build 20201027)
Responsive Width:

PHP: 7.4.33 Page Time: 0.029s Queries: 35 (0.021s) Memory: 0.7138 MB (Peak: 0.7963 MB) Data Comp: Zlib Server Time: 2024-05-24 10:14:50 UTC
Valid HTML 5 and Valid CSS