So what gas are these things SUPPOSED to use? I've read people using reg to premium, but what is the manufacturer recommendation? The stupid Honda manual doesn't seem to say...that or I'm completely missing it the 5 times I've gone through the general info section

 

mine has been tuned to run on 93 with the flatslides, bigger bore, etc.
as far as i know, 87 should be just fine?

 

91 or 93 will only cost a few bucks more, and that's cheaper than blowing the engine due to detonation

 

87 is sufficient.

 

Honda recommends 86 min. Octane is a complicated concept but in simplest terms its a factor of resisting detonation until the cycle of the engine during the compression stroke is ideal. Its has nothing to do with carbs or jetting. Its generally to do with bore size, compression ratio,engine timing, rpm range and persistant internal heat sources. Excessive modification to these areas will effect octane needs. Things like ambient temps and air pressure relative to sea level also impact minimum needs.

Couple of notes- among what's available, an (effective) octane range is worth approximately 1/2 to 1 horse power. And gas generally loses about 1 octane point per week. Something to consider if your bike sits a lot or your tank last you more than a couple weeks between fills.

 

Wow really? I have never heard that before.

If that is the case then most people should run 91+ octane. Because within a month it will be down to 87 !

I have seen gas go bad within 6 months. That's why I never store any of my motors with tons of gas over the winter.

 

Going "bad" is really a different situation but yes. Also something to consider if you buy gas at a very 'slow' gas station as the gas may be in thier tanks for a while before it gets into yours.

However your better to keep a full tank and use a gas stabilizer. There are more potential problems with leaving a tank mostly empty. (rust,condensation,water infiltration,etc)

 

just wanted to bump this thread for obvious reasons, by now there's lots of people on here who have totally forgot to take care of the gas in their bikes.. it's the common thought, ya I'll get to it next weekend..
so people just for reminders: your gas drops one octane point every week it sits!!!
Jay

 

My 29 runs awesome on regular 76 fuel . 91 makes it run sluggish less responsive . Especially that 91 chevron . Ton of ethanol in it !

 

Hey:

From My owners Manual: pg 25

91 Octane RON, no more 5% methanol or 10% Ethanol

It is under Fuel System.

Dub