I have 40:1 and 50:1 two-stroke tools - which I'm inclined to use the same fuel for all of them.
What do you do given some two-stroke tools are 40:1 while others are 50:1?
a) Do you maintain two separate gas cans? b) Do you make it 45:1 for all of them? c) Do you use 40:1 or 50:1 for all of them?
Note: Tools are chainsaw, hedge trimmer, weed whacker, air blower, etc.
How critical is the exact oil:gasoline ratio anyway?
if you use a good quality oil like the stihl oil, you can run everything at 50:1. We even run the old lawnboys which were supposedly designed for 16:1 on 50:1 with out problems.
I would probably use 50:1 in all of them, and make sure it was really really good oil. Echo or Stihl brand chainsaw oil, or maybe Quicksilver synthetic PWC oil.
For 2-cycle tools that I don't use very often, I've starting mixing fuel in a 500ml pop bottle and measure the oil with a syringe. One tank of fuel for most small engines. If you do the same you could custom mix it for each tool.
-Bob
More oil is better for engine life but many engines run poorly at richer oil mixes. I have a 1984 lawnboy designed for 32-1 and I run synthetic at maybe 40 to 46 - 1. Id say use a good synthetic and see how they run and try one mix
Hi, For me, I'll settle for 45"1 with best oil you can get.
Yes, I've got a straight-sided jug that I use to do the same, which I marked off for the tank capacities of different tools. Good tip on the syringe; for the oil I've got a little marked-off cup thing which I think came from a tub of laundry cleaner, but the syringe would probably work better.
I think for 50:1 v 40:1 it's "close enough" that it wouldn't matter using the same mix, but I've got a little tiller which likes a lot of oil and runs on 24:1.
cheers
Jules
I'd go with 40:1 and risk a fouled plug in the 50 engine. If that happens, you can always go lighter, but once the engine is seized, changing the mix won't help.
I am not an expert but I always considered it important enough to mark separate cans for my chain saw and weed eater which use different mixes. I generally use Stihl oil in both.
RonB
The secret is to use good 50:1 oil. Never use an oil that is only designed for 40:1 at 50:1 - and PWC oil is not necessarily acceptable, at any ratio, for air cooled power tools. You want AIR COOLED two stroke oil. (they run hotter than water cooled engines)
It's not just plug fouling - it is also carbon build-up. In Burkina Faso (and many other African countries) they run the oil mix extra strong on their mopeds to keep them from seizing up in the heat - wevery month or so it's pop off the cyl head and scrape the carbon off the head, piston, and ports with a wooden stick..
Smoke like a fiend!!!
Generally they re-use the head gasket - quite often they make their own replacement out of sheet copper, and anneal it every couple times they take it off - just throw it on the fire, pull it out and quench it.
Many of the Mopeds running around in Ougedougou and other cities are OLD colonial era units - Solex, Peugeot, Motobecane, Mobylette? etc from the early to mid sixties. Then there are the later Hondas etc and the new Tomy and other Chinese units. Many of the old ones have very little paint left on them - sun-bleached and worn to a fine patina.
Thanks for that idea Bob. I had not thought of that.
Since the fuel tanks are so very small, that's an option (I'd have to measure each one though and get a syringe, as you noted).
Hi Jules,
Thanks for that tip, on top of Bob's suggestion.
I see if I get the right sized jug, I can mark it for the capacity of each tool, and, ad hoc, mix the oil and gas at the time of fill.
Of course, that's a problem with partial fills.
So, I would have to do a behavioral modification (full fills only allowed).
That's also a maintenance requirement (every 30 hours of run-time, IIRC) for the B&S engine in my mower. The head gaskets seem designed to be reusable, at least to a certain extent. I expect it might be a requirement for a lot of yard equipment, but nobody ever bothers :-)
cheers
Jules
Yes, that's the main drawback. OTOH, I never know how much I'm going to be using each tool each season, and I don't want leftover mixes sitting around, so I just got into the habit of running them dry before re- filling.
I suppose the jug could be marked for fractions of a tank, too, but that's perhaps more trouble than it's worth :-)
cheers
Jules
I've pulled the head oftermore like 60 hours and not enough carbon to worry about on both Tecumseh and Briggs engines with unleaded gas. Bach when gas was leaded it was a different situation - lead/ash/carbon deposits were sizeable and HARD.
Interestingly, the local tool shed strongly advises 89 or 91 AKI (octane rating) of not more than 10% ethanol (which, here in California, is almost impossible not to use).
I'm not sure why they are so strong about not using 87 AKI with the two-stroke motors.
When I asked them about the 40:1 and 50:1 ratios, they tried to sell me this 'stuff' in a can which they say lasts forever and has the oil and gas already mixed (so they were of no real use).
I trust you guys - 'cuz you're not making money off of me - and I can trust your advice.
Small high output 2 strokes are high compression motors - and oil mixed with the fuel drops the AKI significantly - starting with 98 MIGHT yeild 87, 91 might give you 89
I'm not doubting you ('cuz I don't know) ... and I had never thought about what oil does to the octane rating ... but ...
I would 'think' that oil would be harder to burn than gasoline ... so ... adding oil ... I would think ... would RAISE the octane rating.
Are you sure oil lowers the octane rating?
In doing research on the oil & ratio, I find the following tidbits of interest:
- Two-stroke oil reduces the octane rating by about 2 points.
- Two-stroke oil raises the octane rating (by an unspecified amount).
- All Echo 2-stroke equipment requires 89 octane gasoline with ISO-L-EGD & JASO M345 FC/FD two-stroke oil
- Using more two-stroke oil (i.e., 40:1 vs 50:1) will not help your engine.
- Do not use synthetic two-stroke oil.
- Two-stroke oil reduces the octane rating by about 2 points. "First, when fuel is premixed with 2-stroke oil, the octane rating is reduced by about 2 points. An 87 octane fuel would therefore become 85 octane. Second, fuel evaporates and loses its octane rating when it lays in your aircraft's fuel tank or in a plastic jug. A "premium", 91 octane fuel will see its octane rating reduced to unusable levels after as little as three weeks. Fuel with a lower octane rating would obviously have an even shorter usable life. REFERENCE:
- Two-stroke oil raises the octane rating (by an unspecified amount). "adding oil to the gasoline will raise the octane. The amount that it will raise the octane though would be very little. The reason for this is twofold. First, with a fuel-oil ratio on the order of 25:1 - 50:1, there is actually very little oil added to the gasoline. Second, when the oil/gas mixture enters the cylinder, the oil will "drop out" while the gasoline will remain a vapor. this is due the oil's lower vaporization rate. If the oil didn't do this, there would be no lubricating effect and the engine would quickly seize." REFERENCE:
- Using more two-stroke oil (i.e., 40:1 vs 50:1) will not help your engine. "The ratio is 50 to 1, or 2%. This means you would mix 400mL of oil in 20L of fuel, 500mL for 25L, and so on. Using more oil than recommended would not help your engine in any way: it will accelerate the formation of carbon deposits which will eventually break loose and accelerate wear." REFERENCE:
- All Echo 2-stroke equipment requires 89 octane gasoline with ISO-L-EGD & JASO M345 FC/FD two-stroke oil "ISO-L-EGD and JASO M345 FC/FD oil must be used with a mid-grade (89 octane) or premium gasoline in all 1997 and newer engines." REFERENCE:
- Do not use synthetic two-stroke oil. "Synthetic oil should only be used by those who operate their engine nearly every day. Even when shut down, air is constantly circulating through a
2-stroke engine; it is never sealed like a 4-stroke engine. Even though it has excellent lubricating properties, a synthetic oil does not effectively protect a stopped 2-stroke engine against corrosion: it tends to attract moisture and will run off the parts rather than leave a protective coating." REFERENCE:HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.