I noticed in the manual that the CBR600 F4i has 12:1 compression.

That used to mean race gas, before the days of timing retards and such.

I just bought an 04 cbr f4i. I went to put gas in it and though I haven't read anywhere where you need to run premium in it I was afraid to not given the 12:1 compression ratio.

What is the recommended fuel grade to run in the CBR F4i that's not been modified? Bone stock.

Thanks,

Wayne

 

Depending on where you live but just regular ol' unleaded (87ish octane) is all it will need.

 

Regular old 87 has always worked just fine for me. I believe the manual says 86 or higher

 

Yes the static compression is high, but the dynamic compression is low. Massive valve timing, excellent combustion chamber design, all aluminum construction-they all add up to octane tolerance. The bike won't retard timing unless you use something under 87octane if it will at all.

 

Here is a good article on Motorcycles and octane.

If octane is good, is more better? | RoadRUNNER Motorcycle Touring & Travel Magazine

 

Great article, thanks for the link! Now i won't be wasting money, thinking I'm doing a good thing.

 

That article was very informative I will just Jared with the 87 octane.