Octane requirment

[underdog57]

I would like to know the octane I should be running .
I read a ton of stuff on this here , but was interested in what the owners manual says...
This is the 79 xs1100 special ...9.2 comp.

Bob

[JWSanders]

These bikes do like the higher octane a little better, but I have had no problem with any grade.

[HobbyMan]

I run mid grade because its a lot cheaper than premium. I put some toluene and xylene in it to raise it if I need it. A lable on my bike says 91 octane leaded but then again I don't think these bikes need lead. (lets not start a fight now that TC is gone)

[underdog57]

Originally posted by HobbyMan
I run mid grade because its a lot cheaper than premium. I put some toluene and xylene in it to raise it if I need it. A lable on my bike says 91 octane leaded but then again I don't think these bikes need lead. (lets not start a fight now that TC is gone)

Someone painted over the label that was in the side cover ...
mid grade is 89 , that darned close to 91 ..
THanks Guys !!

Bob

[malber]

I've been using regular since I got the bike. Haven't noticed any performance issues and have been getting stellar mileage since I flushed seafoam through the system. What issues could there be with using a lower octane?

And: TC's gone?

[lorenc]

What about 10% ethanol blend? It is also 89 octaine

[skids]

Lower octane should be fine unless your cumbustion chamber volumes are full of carbon gunk which could raise compression. If it doesn't ping, don't fix it!

Originally posted by lorenc
What about 10% ethanol blend? It is also 89 octaine

[TADracer]

What these guys said. I have been running regular and mid grade for years. Regular runs Ok in my bike but the mid grade just seems a bit smother. Might just all be in my mind, though.

The tag says run regular gasoline but the valve seats seem to be hard enough that the unleaded stuff does not bother them.

Ethanol blend is up in the air to me. We dont see it much yet down here in gator land but I know that stuff does promote a bit of corrosion and takes away some of the natural lubticity that straight gasoline has.

[Pat Kelly]

I've used the chea........inexpensive stuff in both bikes with no problems. Sometimes in mid summer I'll use mid grade because it gets hot here and the bikes ping a bit.
Now that I have the bigbore kit in the LG it seems to run a bit ragged on the cheap stuff. Mid seems to satisfy the beast.

[trbig]

What about 10% ethanol blend?

That just means... take your regular gas mileage on regular gas and subtract it by at LEAST 10%!! lol. Seriously, Hobbyman says he gets somewhere around 25% less mileage on a tank with the ethanol. I know I truck I was driving went from 18mpg to about 12 or 13.

All I really run is regular and haven't had a problem. I do think it runs better/smoother on Super... but lately I just can't make myself pay that price. Plus, it's getting hard to find pumps that have three diffferent lines. If the pump is a single hose dispensing all three grades, since you're only getting 3 or 4 gallons.. the first couple are probably going to be regular anyway from the last guy.

Tod

[webbcraft2150]

Tag on the seat says 91 unleaded on my 80g. Cooler weather in NM (5600ft) I could get away with regular, summer required the good stuff. Since it seems to be summer all the time in Texas, I always run preimum grade. The dollor difference between the grades is not a big issue, at least when filling the bike.

[ambidextrous]

ive been running on super since i got the bike

its only like 50 cents, and it gives me some peace of mind for some reason

threat the old girl to some high quality beverages is what i say!

[TopCatGr58]

Originally posted by malber
And: TC's gone?

Hey Malber,

You really must pay a little more attention to the DATE STAMP on the thread posts ...that was over a month ago, I was on a trip!

Yeah, because of the rating of Octane from the owner's manual around 91, and I also have the little big bore, I prefer to run Premium also. And we don't have those fancy computerized ignition systems like cars with fuel injection do to monitor the exhaust air/fuel ratios and automatically adjust the timing to compensate for the lower octaine and load conditions!

Pinging is not a good thing for pistons!
T.C.

[underdog57]

This is on yamaha site for the 79 xs1100sf
found this clicking on service data in the parts section of the site..

http://www.yamaha-motor.com/sport/parts/home.aspx

It says it takes regular gas , not sure what the octane was in 1979??

Mine runs very good on todays reg gas . No engine mods ...

Bob

[underdog57]

Whoops ,
thought that would bring the page up , but you need to go to parts . Then put your imfo in .
I know this has been discussed before me !!

Bob