Just got my Red Face COMPLETLY redone! and thought after a couple weeks of using 85 octane fuel, switched over to 91 octane to see any difference in how much fuel it drank. Machine was running like a clock then changed to fuel and sounds like its got a little miss in it. changed the fuel filter, even changed the plugs in it, checked the timing still does it. So what Im gettin at is, could running to high octane in an old 200 make it run rough??? Got me. Im switching back over to 85, but it takes a couple tanks to get that high octane fuel out of it, so well see.
I doubt hi octane could hurt it. Usually doesn't hurt to run better grade of fuel but the comp ratio is low, probably doesn't need it. Some engines you can advance the timing a bit with better fuel.
I agree with Sberry, The high test gas will not hurt anything, but You sure don't need it. I would look for problems elsware to cure the miss.
Hello welderrwc72, this may sound a little bit strange, but I have had some experience with lower grade fuels working better in certain situations. This generally occurs in certain altitude situations and my experiences were related to motorcycle racing. So don't necessarily think that it's strange that your machine might run better on the lower octane fuel. In most situations the higher octane ratings will prevent "pinging"/"pre-ignition". Just a little bit to consider. Best regards, Allan
Ethanol maybe played a part in the hickuping, but maybe all you needed was a slight turn on the air/fuel screw.
Well after chasing the carb settings all over the place and trying everything in the book, I ran a couple tanks of good ole' 85 octane through it and bingo back to normal. Who'd a thought putting cheaper gas in it from the same station would make it run better.
Glad to hear your machine is running better.
I have stayed out of this one because I have not had time to get into a p...ng match, but here goes.
Higher octane gasoline is not a better grade of gasoline. The word "octane" does not refer to quality but to the gasoline's "resistance to ignition". The higher the octane rating, the harder it is to ignite. Running a higher octane gasoline in an engine that does not require it will not improve the performance but could reduce the performance if said machine does not have a strong enough ignition system to ignite the higher octane gasoline.
Also, with ethanol, there is less energy density per gallon than with straight gasoline so you get less performance and less mileage per gallon. Plus you are running the risk of fuel system problems with the ethanol if your vehicle/machine is not designed to run on ethanol.
Griff
Forum
