Will small amount of Diesel fuel contaminate gasoline and ruin engine?
I have some 5 gallon diesel tanks used only twice for diesel, now I need them to store gasoline. I wasn't able to get every last drop of diesel out before putting gas into them.I would say there was less than an 8th of a cup left inside. Will this slight contamination ruin small engines such as:snow-blower, mower, lawn tractor and other similar small engines?

Such a small amount of diesel in the gasoline should go unnoticed by an engine, especially a small engine.
If more diesel were present in the cans, you might get some smoke, since diesel is an oil, but the amounts you're talking about won't matter.
Maybe. If your engines sound funky then you know what it is…….
only a problem if it was half a gallon or more and you used it in a high compresson car or motor bike motor.
diesel has low octane rating and causes pre ignition in petrol engines
Throw a half gallon of gas in there, then dump it into your car (with a nearly full tank).
This will get most of the diesel out of the 5 gallon container, and it will be VERY diluted in your car's gas tank. No problem.
Then go ahead and use them for gas.
Should not make any difference at all. I used to mix fuels in tins, oil petrol methanol, which ever tin was empty apart from the dregs left in, you might find the machine smokes a bit but not a problem.
no a gallon wouldnt have hurt anything might make it smoke but wouldnt hurt with what you had .. snow blower maybe might not run on it but still wouldnt cause any damage other than having to pour it out i wouldnt put it in a motor that you have to mix the fuel any other motor wil not hurt
I agree with Kelly,won't hurt nothing.Won't even smoke.In the old days we mixed 1 gallon of diesel with 10 gallons of gas( that's when diesel was a lot cheaper than gas),diesel is an oil and lubricates the upper engine componets.