Atco model 1747 Mower

Welcome to the forum.

32:1 sounds a bit strange for a machine of that age when 16:1 using Castrol XL or XXL was more the mix of the day but what's needed is someone with some specific info . The Millers is possibly a of bit higher spec than those oils , so possibly 25:1 would be safe.Silly question maybe, but is the mix ratio stamped into the fuel tank cap?

The operators' manuals of the day were usually fairly comprehensive and usually included engine data, timing and points gap etc and shouldn't be too hard to find but I doubt if there was a specific engine manual, but someone may know otherwise..

The fuel cap is to badly worn from exposure have tried cleaning but nothing showing up thanks for your in-put though.

I've come across numerous mixing ratios for Villiers engines, but the extract below is from a period Villiers Midget operating instructions book. Note that it refers to the recommended oil of the period.

Today's two stroke oils have quite different formulations and they generally require less oil per part of petrol in modern two stroke engines, with a typical ratio being 50:1 in a modern hedge trimmer.

"Today's two stroke oils have quite different formulations and they generally require less oil per part of petrol in modern two stroke engines, with a typical ratio being 50:1 in a modern hedge trimmer."

There is regular and inconclusive debate on wether it's OK to run old engines using modern fully synthetic mixing oils either at the original ratio or the much leaner and thinner (as in the proportion of oil) mixes used today.

I believe in "old mixes for old engines" as one of the functions needed for plain main bearings, sometimes with no or very rudimentary seals, is to provide a degree of sealing . A mix using straight SAE30 or 40 oil performs that task better than a 50:1 mix using fully synthetic oil designed to meet the requirements of modern high output emission compliant engines. Better sealing equates to easier starting and better running, particularly on an engine that is past its best where clearances etc are concerned.

That said, I doubt if a modern 50:1 mix will actually cause any harm to an old engine.

I believe in "old mixes for old engines" as one of the functions needed for plain main bearings

As do I.

I like to err on the side of too much oil. I can always "lean up" the mixture if it's causing running problems.

Speaking of running problems, I have just recently flushed out a 4 stroke mower whose owner's wife filled the fuel tank with some bizarre concoction that had the consistency of castor oil. Unsurprisingly, that one didn't run at all!

The thing to bear in mind when overdosing with oil is that every unit of the resultant mixture contains more oil and less petrol and is therefore weaker in terms of fuel to air and will run proportionately hotter. We were selling a lot of Victa two stroke engined mowers at the time that the UK switched to unleaded fuel and a number of our customers erroneously  decided to up the oil in their mix to compensate for the lack of lead. The result was a spate of engine problems  - wiped pistons and bores etc.

I can remember having interesting conversations with the then service manager of Victa UK who was experimenting with running machines on far leaner (oil wise) mixes with no adverse results. I recollect him saying that so long as the oil and fuel were of good quality and measured accurately no harm would come to a Victa PowerTorque engine run at 60:1 and that he had run a test machine successfully with even less oil; however he would not recommend publicising the use of less oil as owners could not be relied upon to measure accurately!

At one time we sold an Ariens rotary mower fitted with a Sachs engine that ran at 100:1 but only with their "special" oil!

The thing to bear in mind when overdosing with oil is that every unit of the resultant mixture contains more oil and less petrol and is therefore weaker in terms of fuel to air and will run proportionately hotter.

Very good point.

My experience with two strokes is that if you do go overboard you'll soon become tired of oiled-up plugs.

Hi Everyone, 1st thanks for input,I was going to us Millers classic 2 stroke oil (just come in from freeing up the blades). So tomorrow if t is free enough and I have a spark might have a try at seeing if it will fire. I have to decide what I am to keep as the wife is not to happy as I have a Suffolk that works and a Standard that is work in progress just got the "1747" Atco also the modern rotary Which I am told will be  Staying! (ha ha)So it could well be the standard as I have Great memories of an Atco with the "old" Kick start method of starting.