Carburetor Engines and fuel

Does it matter what type of fuel you put into a carburetor engine? I have been told that carby engines cant distinguish what type of fuel is being pumped into it aka how much ethanol is in the fuel, so that means your just burning your money....literatly
Is this true?

unfortunately mudderboike engines with carbs can tell what fuel is being stuck in the tank
all of which has been discussed before ...intypical KSRC fashion

do a search and spend hours reading many posts of a pontifical nature





Smitty

Cheers mate

unfortunately mudderboike engines with carbs can tell what fuel is being stuck in the tank
all of which has been discussed before ...intypical KSRC fashion

do a search and spend hours reading many posts of a pontifical nature





Smitty

Onya Smitty

im running premo, with my carb punk, she hates shell but loves caltex meeee drunk

the carbs may not be able to distinguish what fuel is in the tank but the state of tune of your engine would be able to.

ie if you are running a highly tuned engine producing big HP then it will run bad if you put shit fuel in, inversely if you are running a std street engine and put in prem fuel it may run a little better but you would be basically just burning your money.

Mine runs shit on mobil 98, runs good on their 91, runs even better on BP ultra and about the same on bp 91

the only way it could possibly tell at the carbies is the relative density of the fuel. if the additives to the fuel increase or decrease the density then the engine would ingest differing quantities of the fuel and that in some part would contribute to the leanness/richness of the fuel.

At the engine, well, that combined with the flashpoint/combustability of the additives, the appropriate fuel/air ratio for the additives and the associated increase/decrease of the detonation point of the fuel make all the difference. I.e. if we could get camels piss to have a detonation point and BTU rating similar to ULP then our bikes could run on it. It's not going to care or know the origin of the fuel it uses as long as it works.

Well put, and I just thought I would pre-empt any "but 98 is cleaner" posts. I run mostly 91 in my bike with maybe premium or 98 if it is getting a long hard thrash. I stripped the carbs ysterday for something to do (had them off to do the VC shims), after at least 30,000 k's since their last clean, they were very clean, just a light brown film in the very bottom of the float bowl. Nothing in the jets at all. I don't buy fuel from that garage if the tanker is there filling up, and I try and only buy fuel from newer garages as they have fibreglass tanks( obviously this one goes out the window when touring around).