Fuel Octane, My 2 cents worth, or $4 worth

When I first got my 1100 last year I ran 93 octane, but have slowly migrated to 89 and then 87 with no noticeable effects. It's hot here in Bama, too, but I haven't had any pinging or other heat-related issues this summer with 87 octane.

I do run only Chevron or Texaco, both have Techron, to help keep the carbs clean.

Arrghh!

You guys just made my life more difficult. I'm sitting in a hotel room between days of my MSF class, and was wondering if my friend who said it was imperative that I run high test gas in my '85 Kawi 700 LTD was full of it, and here I find this thread.

His thoughts, which make sense by themselves, is that the engines are high enough compression that they need high test to avoid pre-detonation, knocking, or whatever the technical term is. That, and something about avoiding deposits on the engine internals.

Something to think about while I spend more time on small, dinky, underpowered viberating bikes passing my skills test portion. :woohoo:

xcgates wrote:

Arrghh!

His thoughts, which make sense by themselves, is that the engines are high enough compression that they need high test to avoid pre-detonation, knocking, or whatever the technical term is. That, and something about avoiding deposits on the engine internals.

These kz's are not high compression engines, most are 9-9.5:1. Most the newer sport bikes are mid 12:1 compression. No need for high octane on a stock piston kz.

I have an 84' 700 w/ a friend that told me the same thing. I did it for awhile, then on the reccomendation of this board made the change to 87 & never looked back. It's cheaper & runs just as well. Sometimes friends are full of "it".

KZ700A1 wrote:

I have an 84' 700 w/ a friend that told me the same thing. I did it for awhile, then on the reccomendation of this board made the change to 87 & never looked back. It's cheaper & runs just as well. Sometimes friends are full of "it".

Its just nice to get a spread of opinions. You know, since nobody in my family likes bikes, or anything other than just driving cars, I like to hear what everyone thinks. So I grew up not knowing a thing about cars. Now I just mess with stuff until it works, I break it, or I actually figure something out. Whether or not I'm right. :laugh:

::EDIT::
Just thought I should add that the sticker says to use fuel with a RON rating of 90. But from what I can tell, RON is normally 8-10 higher than MON, so I figure the pump rating should be something in line with regular.

the bike was built at the height of OPEC's oil embargo, at which point 93 might well have not existed. mind you im 26, and have no personal frame of reference to such times, but i think my point is that back in the day when our bikes were built, 87 was intended and designed for. its for this same reason you dont go and throw in synthetic oil into the crankcase, is that its literally too good for the design of the engine...with a wet clutch you start slipping and burning the plates, and is why good old 10w30 works fine and should be used unless otherwise specified. usually 10w40 is is the got-to when specified, and makes sense especially for our lower compression engines; as the temperature drops you need that thicker 40 wt oil to help with compression when the rest of the tolerances have opened up because its freezing outside.

Actually, 87 octane has more potential energy than 93 octane! So, in theory at least, if your engine will run on 87, you will actually get LESS power by running on 93!

Also remember that lead in gas increases the octane by reducing the propensity to "knock" - so putting in 100LL avgas really does nothing for you, and will cause all sorts of lead deposit problems - don't do it!

The one that always makes me laugh is the stories of guys who put "jet fuel" in their cars/bikes and claim huge performance gains! Trouble is, jet fuel is actually diesel and most spark-igntion engines won't run on it at all!