Have the nitro tank turned off---use a hotter plug---start on the gasoline and use what ever matter you have to keep it running (continue spraying but at a rate where the engine runs decently) when you get some heat in the cylinders( may take a few minutes or more) turn on the nitro, when it gets loud shut off the gasolene spray/drip

Lots of guys would make a little gas tank that they could set on top of the blower/injector with a drip/spray bar that would put gas into the injector hat. when cylinder got heat/ turn on fuel shutoff valve, engine gets loud, shut off gas/alcohol

after engine is warmed up--do your stuff--change sparkplugs to race heat range, refill fuel tank, etc

Lots of guys would put like 30 % to 50% mix in, prime with gas and then run for warmup , drain tank/ fill with race percentage

Whatever you do know what you have for fuel in what can,etc