Topic: Octane?

[Gordon]

I always use premium or the highest octane possible since as pointed out they were designed to run on regular leaded gasoline and without the lead now higher octane is prudent

Incorrect.  All of the sohc4 bikes were designed with unleaded fuels in mind, and almost all were meant to run on gas with an octane rating that is the equivalent of today's 87 octane (in the U.S. octane rating standard). 

Go back and read the entire thread.

[Retro Rocket]

I always use premium or the highest octane possible since as pointed out they were designed to run on regular leaded gasoline and without the lead now higher octane is prudent

Incorrect.  All of the sohc4 bikes were designed with unleaded fuels in mind, and almost all were meant to run on gas with an octane rating that is the equivalent of today's 87 octane (in the U.S. octane rating standard). 

Go back and read the entire thread.

Not trying to be argumentative Gordon but we didn't get ULP until 1980+ the sohc 4's were all but gone by then.
I have never had any problems running higher than 87 octane in my bikes and Terry does the same with no problems at all. Why do you think they will run better on low octane fuel.? In my experiences they are more likely to ping under load with lower octane fuels......Curious

[Gordon]

I always use premium or the highest octane possible since as pointed out they were designed to run on regular leaded gasoline and without the lead now higher octane is prudent

Incorrect.  All of the sohc4 bikes were designed with unleaded fuels in mind, and almost all were meant to run on gas with an octane rating that is the equivalent of today's 87 octane (in the U.S. octane rating standard). 

Go back and read the entire thread.

Not trying to be argumentative Gordon but we didn't get ULP until 1980+ the sohc 4's were all but gone by then.
I have never had any problems running higher than 87 octane in my bikes and Terry does the same with no problems at all. Why do you think they will run better on low octane fuel.? In my experiences they are more likely to ping under load with lower octane fuels......Curious

I can only imagine that Honda knew that leaded gasoline would soon be going away in the U.S., so they built their engines to run on unleaded. 

I don't recall saying that the sohc4's run better on low octane fuel, but I have stated in the past that unless you have made modifications to your engine that would require a higher octane gas, or you have excessive carbon build-up in the combustion chambers, then you will see no benefit from running the more expensive higher octane. 

[Blueridgerunner]

I was in the gasoline (petrol to all my friends in the UK) business before I retired. If you have an unmodified bike it should run on 87 just fine. The ethanol E10 that is about all we can get around here is equivalent to the non ethanol 89 octane rating anyway. However, if it makes you feel better, then go ahead and run higher octane. Won't help much, but won't hurt.  Just as an aside, one of my customers I delivered to was the North Carolina Highway Patrol. They used regular, and it didn't seem to slow them down any.   

[VTCBike750]

Soooo, Found ethanol free gas , but its premium only.  Stick with low octane and get the ethanol or go for the premium, pay more, and get carbon build-up?

[TwoTired]

Ethanol free, for sure.  Not for how it runs, but ethanol fuel in the system, attacks rubber and the chemistry leads to corrosion of metals in the carbs.

Understand that if the fuel is constantly flowing, being used and being replenished, only the rubber bits suffer.  If the fuel sits in the system for periods of time, that's when other compounds form in the fuel and attack/convert the metal parts.

Cheers,