I went to Acura and explained what had happened. They had seen it before. By the way, there is no drain plug on the RSX tank and the fuel filler line is 'siphon proof'. Since my mix was about 50/50 gas/diesel, it was a question of getting the engine temp up to the point where the diesel would combust. 15-20 starts (with caughing and a lot of smoke) I got it to stay running. Wedged a piece of wood from the seat the the gas pedal. 13 hours later (at 3000 rpm) the tank was empty and I followed it up with a full tank of high octane. Runs like new.

Looking back, I supposed I could have disconnected the fuel line and put 12 volts to the fuel pump- which understand puts out 60 psi. But then I would have bad fuel to get rid of (I dont mow my lawn that often...).

Anyway, thanks for your comments/help. You would not make this mistake - but according to Acura, they see it often - so you can help if it comes up on the forum again. p.s. the rsx has no splash flap in the filler neck like 99pct of cars do - that would have prevented the problem in the first place