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Main Area => General GS500 Discussion => Topic started by: Susuki_Jah on September 16, 2004, 10:35:15 AM

Title: A few things I need to know?
Post by: Susuki_Jah on September 16, 2004, 10:35:15 AM
OK first off. it takes my bike about 5 mins to warm up properly. Does this sound right?

second I started putting 93 octane gas in my bike. runs great. but last night in 6th gear at full throttle I started missing. right under full throttle it was fine but as soon as I hit it it would missfire. So I slowed down hit a light then start back up again. and no problems. just wierd that it randomly came and then went.

what is the best octane to run in our bikes?
Title: A few things I need to know?
Post by: SPARKPLUG1977 on September 16, 2004, 10:50:05 AM
run the cheap stuff.
Title: A few things I need to know?
Post by: manofthefield on September 16, 2004, 11:06:45 AM
and 5 minutes is about right for warm up, depending on ambient temps
Title: A few things I need to know?
Post by: Susuki_Jah on September 16, 2004, 11:43:44 AM
yea about 70 degrees.

so the best to run is 87?
Title: A few things I need to know?
Post by: scootr9718 on September 16, 2004, 11:47:52 AM
Quotebut last night in 6th gear at full throttle I started missing. right under full throttle it was fine but as soon as I hit it it would missfire.

this is probably a fuel delivery issue...sometimes with the GS's, at high speed, the fuel vaccum isn't enough to get the gas to the carbs...if this happens, try switching the petcock to PRI...usually solves the problem.
Title: A few things I need to know?
Post by: indestructibleman on September 16, 2004, 12:04:00 PM
87 is fine.  the owner's manual says 85 or more.
unless your engine is pinging there is absolutely NO advantage to running higher octane gas.

cheers,
will
Title: A few things I need to know?
Post by: Susuki_Jah on September 16, 2004, 12:05:35 PM
this helps alot thanks guys.
Title: hmm...
Post by: coll0412 on September 16, 2004, 02:39:56 PM
I did get the owners manual with my bike, but under the seat there is a white sticker on the fender, it says

"Fuel: Unleaded Gasoline; 91 min RON"

I would assume that is 91 octane min requierment
Title: A few things I need to know?
Post by: SPARKPLUG1977 on September 16, 2004, 02:52:11 PM
in a perfect world with every last bit of stock compression.
Title: Re: hmm...
Post by: mjm on September 16, 2004, 03:34:47 PM
Quote from: coll0412I did get the owners manual with my bike, but under the seat there is a white sticker on the fender, it says

"Fuel: Unleaded Gasoline; 91 min RON"

I would assume that is 91 octane min requierment

There are two different ways of determining octane - one is the RON (Research Octane Number) and the other is the MON (Motor Octane Number).  MON is usually quite a bit lower than RON.  United States regulations require pumps be labeled with the RON+MON divided by 2.

91 RON plus 80 MON is about 85 in the US system.  For info on what RON and MON really mean check out http://chemistry.about.com/cs/howthingswork/a/aa070401a_2.htm[/list:u]
Title: A few things I need to know?
Post by: Roadstergal on September 16, 2004, 04:59:03 PM
...and the RON+MON/2 is known as AKI, anti-knock index.  That might get you a Trivial Pursuit pie slice, or someting.
Title: A few things I need to know?
Post by: ericjmense on September 16, 2004, 07:56:45 PM
I thought higher octane burns clearer so it would be better to run gas that creates less carbon build up right?  Or am i missing something in my logic?
Title: A few things I need to know?
Post by: ericjmense on September 16, 2004, 08:22:24 PM
Title: A few things I need to know?
Post by: indestructibleman on September 16, 2004, 09:00:53 PM
the only thing higher octane does differently is detonate later.
higher levels of compression will cause gasoline to detonate sooner.  this is pre-ignition, otherwise known as knocking.
so engines with higher compression ratios require higher octane.
an online friend who's a certified honda master mechanic and former pro racer laughs about all the people he sees at track days paying outrageous amounts for race fuel to put in their streetbike engines.

http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm

cheers,
will