I have a 2003 Arctic Cat Firecat 700 EFI Sno Pro that has a switch for Regular or Ethanol fuel. My question is if I have a tank of Regular gas and burn up half of it and then add gas with Ethanol in it (so I have half and half) do I need to flip the switch to Ethanol? Can I hurt the motor without ever switching?
Well, depends on who you ask. I’m sure your Arctic Cat dealer would tell you to flip the switch (or use the jumper plug) when you have a full tank of Ethanol. I don’t think it matters much if you had the half and half scenario you suggest. That being said, we have run every single one of our Cats at the Regular setting here in Minnesota for as many years as I can remember and have never had an issue with it. Never. Sure, we busted stuff, but never has it been a lean burn down attributed to not having the jumper or switch set properly.
It also depends on your exact set-up, to a degree. If the sled is bone stock, the switch gives you some extra fuel to add a margin of safety. Nobody wants a sled to quit running when you’re ten miles from a road, or fifty miles from your trailer, or further. We know that ethanol is the fuel leans the mixture, so anytime you are running hard and the sled might need a little more fuel to keep the piston crown cool, using the jumper is a good idea. Wet, heavy snow? You might want to sue the jumper. Long, hard pulls? Same deal. Questionable fuel, like at that resort on the lake in the middle of nowhere in late December, likely selling left over boat gas from September? Use the switch. Some engine mods added that might make it run leaner and stronger? You should get the idea. The switch and jumper are a safety feature, and helps keep the engine protected if you should hold the throttle at the same midrange position for three miles and melt a piston during the warranty period when using ethanol fuel. All that being said, we have NEVER used the ethanol switch or jumper, as we’re always trying to find the limits. So, if you burn your sled up, don’t come looking for us!