|Quoting flanker (Reply 49):|
It has a better burn
No it doesn't. It is less volatile so it resists burning so it can be compressed tighter before the sparkplug ignites it. Flighty is likely needing higher octane fuel in his lower compression ratio (not compression in general, but compression ratio) engine because of high amounts of carbon in his combustion chamber. The high amount of carbon has increased his ratio. This is probably due to the carb problems he is describing. One of issues sounds like a rich mixture/choke condition which will cause excessive hydrocarbons out the exhaust and carbon build up. It can get bad enough that a valve or two can stick open making the problem worse. These are problems most drivers haven't thought about in years because we all got used to our fuel injected cars. To the professional technician who still sees carbureted engines this is something that comes up. Marine Mechanics in freshwater areas (older boats are very common) see it more often. Get a carburetor out of adjustment and you will be amazed how crappy an engine will run. Speaking from experience I meet a lot of people who think they can make a carb work good. They actually have no idea what they are doing, they just adjust the mixture and idle screws and make things worse.