Best Type Of Gas To Use

Can anyone tell me what the best type of gas is to use with my 1980 kz 550c and 1981 kz 650h

i am running both bike on the top gas but was wondering if this is necessary to do so or if i could drop them down to regular?

thanks
Dave

Regular gas is what these motors were designed for, unless you've done some major modifications (big bore kit, etc) I used to run premium but found it to be a total waste of money. I used to advance my initial timing ala hot rod style (needed premium then) but have since gone back to stock specs and regular fuel. Bike actually runs better too.

Use 87 and see how it runs. If it doesn't ping, use it. If it doesn't run right, try 89.

So here's an update to this question.

Switched to regular 89 gas and the bike runs great! Much better than with the 91 or 93. In fact I was experiencing some mild hesitation on the low range and it felt like "pulsing" at an even speed with about 4k on the revs. I was thinking that maybe some little blockage in the recently cleaned carbs was causing this. Changed the gas and wow...... the 'pulsing went away and also the low revs pick up much improved.

Thanks for the tips!
Dave.

If the station I'm at is not selling 10% ethanol I get 87.
If the station is selling 10% ethanol I get 89.

Avoid ethanol if you can help it... it'll dry out all the rubber parts of your fuel system.

My KZ110A2 runs better on mid grade in the summer and regular in the winter. My KZ1100D runs better on hitest in the summer and regular in the winter. I just did a ring job on the A2 so that might change as the rings seat. I only have a couple hundred miles on it. It does run better each day. Depends on the bike, I guess.....chris3

slowman wrote:

If the station I'm at is not selling 10% ethanol I get 87.
If the station is selling 10% ethanol I get 89.

Avoid ethanol if you can help it... it'll dry out all the rubber parts of your fuel system.

Unfortunately, you can no longer avoid ethanol. It used to be only the "cheap" gas brands had ethanol, but our beloved President said that in order to save oil(?), we must all use ethanol! In MI, they used to have a placard on the pump stating it contained ethanol - no longer! There is a simple test to figure it out if you are interested.

I doubt if any of our bikes will be affected by it, they are new enough that the effects of ethanol in fuel were known, and avoided. But if you have any gasoline powered equipment from the '60s or early '70s, be careful. Fuel lines and carb seals are the most likely problems!

I used to run Sunoco 94 religiously, then ended up with a tank of 87 octane a few summers ago during a major blackout. I haven't used anything but 87 since.

Unfortunately most non-ethanol stations in Madison, WI are gone. We are luckier than most of you who have no choice but ethanol or no gas.

For reference, if anyone is in the Madison area... the ONLY non-ethanol station in Madison, WI is now Bennett's Sinclair on the corner of old Highway 12 North and Century Ave. way up in Middleton. There was a Shell that just switched over the other day. Bennett's is the ONLY place I go for gasoline.

My car doesn't like ethanol either. I have an old '84 BMW 3 series and the Motronic 1.0 computer just doesn't know what to make of the 10% corn!

ethanol is a waste of corn that could be used to make good whiskey!if you must use ethanol try putting about 1/4to1/2 cup of marvel mystery oil in the tank(Full Tank) it will help keep the gaskets and o rings in the carbs from drying out.

I do something similar with my fill ups. I use 85 and every once in a while I add gumout injector/carb/ valve cleaner. That stuff has a 3 in one oily residue which is like a lotion to the rings.

For those that don't know, remember this:

Octane is a detonation (and ignition, for that matter) INHIBITOR.

The higher the octane, the LESS likely the fuel is to completely burn, or detonate.

High octane fuel is only required in engines with HIGH(er) compression to avoid detonation.

Some people who have normal engines use the next octane up (89-ish?) when in extreme conditions that might increase the likelihood of detonation (pinging); like extreme heat, etc.

All of our engines, unless modified for performance, should be running on regular ol' regular.

The use of high(er) octane fuels in our regular engines will only cause hesitation and carbon build-up from unburned fuel.

...Okay, I re-checked the above for accuracy, but if anybody catches an error there, let me know....