Because a 40:1 ratio has more oil mixed in with the fuel it is possible to run a 50:1 engine with that mix. I would caution against it though as it may cause future problems. Too much oil will cause it to smoke more and can foul up your spark plug which will cause your machine to run poorly or even stop running. The excessive oil may gum up other parts of the engine as well.
I would recommend having 2 gas cans around, one marked 50:1 and the other 40:1. That way all your machines run as they should.
Linden,
Thank you for your thoughts. I relize that I may see a little additional smaok and the plug may foul, but fulling with multiple gas cans with different mixtures is a pain. I already have a can with regular gas, a can with 40:1 and a can with premium gas. I thoink I am going to run the 40:1 in the equipment requiring 50:1. I change the plugs every fall anyway.
Thank you for you input
Tom
Tom,
The problem with running a mixture different from factory specs are as follows. The reason for 50:1 mix is the quality of the oil is better now. The quality of the fuel is worse. When you now mix the fuel 40:1 rather than 50:1 you are lowering the Octane of the fuel. This can cause pre-ignition and engine damage.
I would recommend running all of the equipment on the factory specs. Always run an oil that has a JASO-FD rating
Tom,
The problem with running a mixture different from factory specs are as follows. The reason for 50:1 mix is the quality of the oil is better now. The quality of the fuel is worse. When you now mix the fuel 40:1 rather than 50:1 you are lowering the Octane of the fuel. This can cause pre-ignition and engine damage.
I would recommend running all of the equipment on the factory specs. Always run an oil that has a JASO-FD rating