What octane of gas are you using?

[jays-cb750]

What octane of gas are you using? From what I can find it looks like it needs 86 or 87 is this right? I have an 82.

 

[dirtdigger]

87 the minimum for a stock motor. If you have raised compression you will need higher. I run 91 in my stuff.

 

[K2750tracy]

I always run 92 in both my 72 sohc and my 79 dohc. The high octane has less ethanol than lower octane and we all know what ethanol does in these older carbs!

 

[dirtdigger]

Our low grade 85 is 100% gas our 87 is 10%ethanol and our 91 is 100% straight gas. Dont get me started on ethanol fuel I was an auto mechanic and I have seen the problems first hand. Plus I would rather eat corn then burn it in my motor.

 

[Travis]

Yeah I run premium (91-93 octane) in all of my motorcycles, boat, lawn mower, etc because around here it is ethanol free. The only thing I run regular in is my car and truck.

 

[joe p]

Yeah I run premium (91-93 octane) in all of my motorcycles, boat, lawn mower, etc because around here it is ethanol free. The only thing I run regular in is my car and truck.

I do the same.

 

[cafeken]

93 octane in all my bikes and my boosted mustang but its all has ethanol down here in south Florida it sucks that ethanol is bad news if your bike sits a week at a time think im going to run race fuel with no ethanol in my 78cb cause it sits

 

[broncomatt]

Yup, nothing but super in my honda's and my bronco.

 

[hje_326]

I can't remember where I saw it but someone recommended jetting the carbs the next size up because of ethanol. Is this a smart move?

 

[kramdua]

is it true the higher the octane the less ethanol? i thought 10% was all fuels except ethanol free.

 

[brettp]

The higher the octane, the more compression resistant the fuel is to premature combustion. I could have put that better, but long story short, unless your vehicle/bike has a compression ratio of something like 10:1 you don't need the higher octane.
The ethanol percentage is up to the company creation the gas and the government mandate to do so.

 

[kramdua]

we have 90 ethonal free i use.
thanks,

 

[Jeffry Gagnon]

we have 90 ethonal free i use.
thanks,

I've used 87 octane, corn alcohol, "Regular" in my 84k mi. '91 since I got it (@19k mi). In CT, it sits garaged for 4-5 months each year). Winter prep is only:
1. Tires up off unheated garage floor.
2. Shut the pet, fire it up, and run the carb bowls dry.
3. Treat the gas in the tank and fill to the top.
That's it. Have NEVER had a problem from ethanol clogging the jets or lines, or gumming up in carb bowls.

Also -- no need for more than 87 octane gas, unless you're running a high compression engine (which the CB750 is NOT). Same with most cars today. Use the octane rating on the sticker or manual. As with the CB750, it's almost always 87, even on a newer six cylinder car.

"You get no more power at all with a higher octane fuel than the engine was built to use. All you do is spend more money." Got that from YouTuber Scotty Kilmer about ten years ago. As usual, he was right.