What octane should I be running?

Hey guys. My 83 kz650 csr is finally on the road and runs great! I was wondering, what grade a gas should I be running. So far I've burned two tanks of regular. I know it's an older bike so I'm wondering if I should be running a higher octane fuel. Also should I also be adding lead additive to it?

The owner's manual probably says "87 octane or higher" [(ron + mon)/2]. It may not specify unleaded, but most if not all new vehicles w gasoline engines sold in the USA by at least the late 70s were probably required to burn unleaded fuel. There may be a label on the motorcycle somewhere. I usually alternate between 87 & 91 and occasionally add 93 to ensure the octane rating stays above 87. maybe not necessary, but that's what I do to avoid pinging which might occur under certain conditions, especially in the hot hot summer months (theoretically).

I run 93 octane Shell, Exxon, or other "Top Tier" gasoline (see link below for info on "Top Tier) in my 1977 KZ650-C1. I know many others run lower octane, but when I bought the bike new in 1977 the dealership said to run the highest octane I could buy. I've never had any fuel related issues at all; the bike now has more than 61,000 miles on it, and the valves have stayed in adjustment all that time. Maybe it's a coincidence, but that's what works for me. Ed

www.consumerreports.org/car-maintenance/...e-worth-extra-price/

Like Eds dealer recommended .
Run the best gas you can.
After all. How much are you putting in your tank gallons / or price wise
Gasoline like everything else is not the same as in the 70's
I miss Sunoco 260 at the pumps.
Today I run premium all the time , or Turbo Blue if using lots of boost.
Dave

I have heard that the lead that used to be added to fuel would help to lubricate the bronze components in the valve train. So if you have an older head you might try a bit of lead. (:laugh: :laugh: :laugh:) sorry . Some race fuels still contain lead and there are additives. Will they help ?

Mix in a gallon of VP110 to three gallons of pump gas and you have a fuel that you will never have to worry about denotation or any other motor problems associated with a low octane fuel. Plus it has a good amount of tetraethyl lead so your valves and valve seats will benefit from it too!!!!!

OR
79 Dollars for 5 gallons plus shipping and tax

Run whatever you want. As long as you don't have detonation.
If you hear detonation, use a higher octane.

"Octane rating is simply a measure of a fuel’s resistance to detonation – it is not about horsepower or heat energy. Octane does have a significant impact on how an engine performs because it is the enabler that can allow an engine to reach its peak potential before encountering detonation." David Reher of Reher Morrison

rehermorrison.com/tech-talk-92-the-detonation-investigation/

F64 wrote: Run whatever you want. As long as you don't have detonation.
If you hear detonation, use a higher octane.

"Octane rating is simply a measure of a fuel’s resistance to detonation – it is not about horsepower or heat energy. Octane does have a significant impact on how an engine performs because it is the enabler that can allow an engine to reach its peak potential before encountering detonation." David Reher of Reher Morrison

rehermorrison.com/tech-talk-92-the-detonation-investigation/

There is ZERO advantage with running high octane fuel compared to regular unless the engine is detonating, and my bike doesn't detonate on regular so that's what it gets.

I agree with the comments regarding octane. Most older bikes were low compression, requiring only regular fuel with an octane of around 87. Newer bikes with high compression may require higher octane rating. The issue for me in older bikes is ethanol, which interestingly increases octane rating.

Gas in my neighbourhood contains up to 10% ethanol, which I try to avoid if possible. Several retailers offer premium without ethanol so that's what I buy for my vintage fleet. For my KLR I buy regular with ethanol.

This site allows us in NA to find stations with ethanol free gas.

www.pure-gas.org/