Modern Fuel

[Roger Ackery]

Hi, I think 98 Octane is to dense a fuel for my Kettle.. she seems to run better (smoother) low speed on 95,I have friends with GT550's that use 98 with no problems, maybe the air cooled bikes aren't as sensitive to the higher octane ? I've also discovered recently that the left hand carbie air screw was way to rich, this explains the very wet and messy exhaust pipe end, I'm surprised the spark plug didn't foul ? Has anybody else found any running issues with 98 fuels

[Alan H]

Well the Hippo ran better on 98 when the L barrels were on and the engine was higher compression, but now with A barrels doesn't seem to make any difference either starting or running, so usually gets 95. This has ethanol in it as we all know, so I try to run the carbs empty if it's not going to be run for a few days. Running wise is generally 'touring' and not as much local back road work.
The 550K didn't mind what fuel it had as it was standard compression, so usually got 95, with maybe every 10th fillup as 98 for a treat which would flush the crappy ethanol out of the carbs. Mixed running and didn't get much high revs.
The Earwig is diferent however, 98 whenever I can and definitely runs better (ported and skimmed heads) and doesn't run as well on the cheap stuff at all. Usually gets a good spanking when out and seems to thrive on it!

[Roger Ackery]

Hi & thanks Alan,all the big name Oil Company's here don't add Ethanol to 98 or 95 at all
We can also get 91 without or with 10% Ethanol a State Government stipulation to the Oil Company's At higher revs she loves 98 gave her lots of high rev range running tonight... scared myself once or twice
Will switch back to 95 & monitor the performance over the same bit of road