OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Tech Talk Two Stroke Oil?

Ok, so I hope I don't start a war here, but I have a question.

I ride dirtbikes (2 stroke) and I usually run them on Motul 800 (Full synthetic oil) or Maxima Castor 927 at 40:1. Is it ok to use some of the fuel in my lawnmower? I know it is probably a waste because it is pretty expensive but it does smell awesome! And there is no better week fix than getting all geared up in my riding gear and mowing the lawn!

Hi dirtbikersa,no mate you won't start a war here...we're a friendly bunch and enjoy getting tricky questions!

So onto your question....to answer it and to give you good advice, we need to know a few details of your lawnmower. Obviously it is a 2 stroke, but we need to know a little about your machine....Make, model number of the machine, and engine number and make of engine. Pics of your machine and engine would help with the ID.
I think you will be OK, but what fuel are you using in the mix?
We are recommending that the ULP is Premium, because some Independents and some well known brand operators are using ethanol in their blend (10-12%). This is not good for outdoor power equipment, and can cause 'o' rings, seals and gaskets to prematurely fail and to foul carby's, no end.

A word of caution on that castor oil mixture: castor oil is not really compatible with petrol, and will not mix reliably with it. It isn't really a great idea to use such a mixture in any 2 stroke, but because it isn't likely to reach high temperatures in an unmodified lawnmower engine, there probably won't be much varnish formation. You can use castor oil as lubricant in an engine fueled by straight methanol - castor oil is compatible with that. Of course the methanol is obnoxious in several other respects, but at least it will mix with castor oil.

I rather like the smell of burned castor oil myself, but the safest way to enjoy it while mowing is to put a very small amount of castor oil in the straight petrol fuel of a 4 stroke lawnmower, and keep its sump filled with an automotive-rated mineral oil. I've known vintage racing car enthusiasts to adopt that solution, with the support of an oil company (the oil company tech rep advised them never to put it in the sump, however, if they were running the engine on petrol.)

ha ha, thanks for replies. I have a Rover Suzuki mower that is currently playing up and just picked up a old Victa Hawk 2 stroke that is going but the carb is leaking.
I normally run 98ULP in my bike and on the rare occasion some AVGAS. But I would not run AVGAS in my Lawnmower! Grumpy you are correct about the Castor, it does not mix well with AVGAS but never had any problems with 98ULP. I have used Castor oil for years in my race bikes and always had great results.
This is often a topic on which 2 stroke is better, Castor or Full Synthetic.