Oil/petrol ratio and modern 2 stroke oil

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    Good afternoon. What is the current thinking on the oil / petrol ratio on Villiers 11C engines. I have mine running but it is very smoky and has a tendency to oil the plug. I’m tempted to reduce the oil content and would like some experienced opinion. I’m also tempted to use modern 2 stroke oil. Any thoughts?

    Many thanks for any comments, Donald.


    I use Exol Optima Racing 2 Stroke fully synthetic oil in all my 2 stroke engines. When used in my SIMAR 56a, it produces virtually no smoke. I also use it in a ratio of 20:1 instead of the recommended 16:1.
    I have a number of vintage chainsaws which originally specified a mix ratio of 16:1, but I use a mix ratio of 25:1 without any issues.

    I would try a fully synthetic oil in your 11C, but keep the mix ratio as originally recommended and see how you get on.



    16/1 is the correct ratio for the 11c , straight 30 engine oil should be used ,and most definately not any modern synthetic type oils.
    The crankcase bushes in the 11c rely on a film of oil to retain crankcase compression , which can’t be achieved with more modern oils.
    It will appear smoky and oil the plug if not put to work , give it some stick and you should notice the difference.



    This is of interest to me as well. Andy, how do you know all this stuff?


    A lifetime fiddling with engines.



    Castrol R at 16:1 smells amazing in my 2 stroke Howard Bantam. It runs really well on it too. Couldn’t possibly comment on how good it is for the engine in long term though.


    Vintage spec oils for vintage engines – particularly if they have plain bushed bearings.
    Millers do a Classic two stroke mixing oil and Morris Lubricants do straight SAE 30 and 40 non detergent oil that is fine as a mixer.


    I use either Castrol XL or Morris oils SAE30 in my 2 stroke machines. There is an old film on the British Pathe archive which shows an old SIMAR 10 working and that is smoking. The Rototiller is towards the end of the film at 4:10 onwards, I think it may have been filmed at Wembley Stadium.


    Good morning gentlemen and many thanks to those of you who commented. As usual we have two “ experts “ diametrically opposed. What’s new? I have to make up my own mind.
    More interesting than petrol/oil ratios is the following:- Having totally striped the engine and rebuilt it, to make sure I wasn’t loosing crankcase pressure, I RESET EVERYTHING and pulled the string. Nothing, not even a cough. I had fitted a brand new spark plug which came with the “ bits “ I had bought, an NGK AB-6. I don’t know why but I remembered I had an old plug, it turned out to be a Lodge H1. Probably 1930s or even 20s.I took it to bits, cleaned it, fitted it and hey presto, COMBUSTION, I purchased a new plug, a D14-GS Champion and the engine is running fine.

    Any more “ expert “ thoughts? Thanks Donald.

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