Octane

[XS1100_OEM4ME]

+1

+1 H.B. If you are running way too lean you will run way too hot the "ping' can be octane and timming even if not lean, and can kill a motor fast.

In my drag racing days, I drove my car to the track, filled up with Sunoco 260 (airplane fuel) at the pump, then set my timming by ear, took the cooler of beer out of the trunk, droped the rear tire presure down to 10lb's and ran in the 11's. then if nothing broke drove it back home

The piston valve problem happened driving to work, de-tuned for the street and short on cash for the Sunoco 260 gas That was back when they had just started to go un-leaded on some fuels and they were messing around with all fuels and useing us old timmer's car's as ginnipigs

All my friends were hot rodders and many motors started over heating or failing We all had temp gauges and you could see a differance as too how fast it would bypass the thermastate. The Auto Part stores started selling lead add. till Uncle Sam stopped them

Todays prem gas have additives to controll and remove carbon deposits on valves and pistons and they "CLAIM" motors are cleaner when you use them

[Cuda 69]

I run low octane in my bike and have tryed super,couldn't tell any differance.Most (holes in pistons) are caused by running the carbs lean,as has been said on here and by the unfortunate owners.I do make sure I run a tank of quality fuel through the tank from time to time,(Cleaning additives). Yammie recommended regular leaded to be run in these bikes,it's in the owner's manual,and even though the mixture's have changed ,I do believe the octane has stayed the same. When I was an auto mechanic,most pinging was directly related to the timing,timing to far advanced will cause pinging.

[XS1100_OEM4ME]

How octane is caculated now and back in the day is completly different, but that is a whole different subject. The lead was the big diff and why Yamaha recomended reg grade, gas with lead reacts different then without, but we can't have baby's with two heads If a bike runs great on whatever one is useing, thats great + one can save enough to by a candy bar per tank with the cheap stuff