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thanks

I’ll admit to not knowing much about appropriate octane ratings and their application. It’s just that the only alcohol free fuel in my area is 93 octane.

doakley wrote: 09:54 pm Mar 05 2021 I’ll admit to not knowing much about appropriate octane ratings and their application. It’s just that the only alcohol free fuel in my area is 93 octane.

That seems pretty common in some areas. Your bike will run fine on 93 but the only advantage is that it has a longer shelf life than 87. If you store fuel long term it is probably worth the higher price.

Like most mass produced engines our KDXs have pretty low compression. Less than 8:1. There is certainly no need for high octane fuel.

Wonder what the compression ratio is after the RB head mod on the 220?

It includes milling the head so it definitely increases the compression. It says on his website that it is set up for premium pump gas so it is probably a fairly significant increase in compression.

https://www.rb-designs.com/rb_designs_llc_005.htm

It was a fairly significant difference in performance. I live on the NC coast where large outboard motors on fishing boats are more common than Ford F series pickup trucks. Several local stations carry alcohol free 93 octane for that market.

After installing the RB head I figured out I had to run 91 in it. Otherwise it would run hot.