Triumphrat

NewOldSkool · 09-20-2007

Is there any benefit to running high octane on a pretty much stock bike (note minor mods in sig.) I have been trying to experiment with different levels, and it seems to run best on 91, 93 is alittle weird (jumpy almost), but it doesn't do as great on 89 like the book suggests. Would valves play a part in this, as I am coming up to the 2 year mark?
Mondo

sweatmachine · 09-20-2007

stock bike, 89 octane, end of story.

Weasel Pete · 09-20-2007

Generally, air cooled engines run hotter and may have a tendency to pre-ignite or detonate especially on warm days while sitting in traffic which is why the higher octane gas runs better in some cases. Not all pre-gnition or detonation produces a sound loud enough to hear. You can also try cooler heat range plugs.
http://en.wikipedia.org/wiki/Pre-ignition

Diego · 09-20-2007

> Is there any benefit to running high octane on a pretty much stock bike...

No. Unless you have changed compression ratio significantly, there is none. Higher octane has higher resistance to pre-ignition; not higher energy content or any other magic properties sometimes associated with it.

> I have been trying to experiment with different levels, and it seems to run best on 91, 93 is a little weird (jumpy almost), but it doesn't do as great on 89 like the book suggests.

I suspect this may have more to do with the cleanliness of the filling station's tanks than anything you would notice from an actual difference in octane numbers. Try your experiments using gas from some other station(s) and see.

RonD · 09-20-2007

with the bonnie i have used premium unleaded and standard unleaded fuel, and the bike did not know the difference , (plug chops and the way it ran confirmed this ) and why would it on a bike like a bonnie,
but if i try that trick on my old rocket 3 and run anything but premium theres hell to play, so what iam saying here run either but as far as iam concerned premium is a waste of money on a bike that does not need it..

Normandy · 09-20-2007

I like just up from regular, 91 or 92 cause it's cleaner fuel with less chance of getting my carbs crudded out. Not because the engine needs it.

NewOldSkool · 09-21-2007

Thx guys, wasn't sure if it was just in my head or not... but thinking that you might be right about station quality rather then gas. But will have too see as I try to remember which ones I used and when.
Mondo

CAPTDON · 09-21-2007

Wasnt aware of that but no BOOM!! Knck sensor= marbles in a trashcan. If you hear them its sensing! Bikes w/ EFI have sensors of some sort I am surwe like new cars. All wil have EFI soon so want carbs- get em now!! I am sure thet will work in flex/ E-85 soon as well!
THE TIMES THEY ARE A CHANGIN FAST!!! A time will come some day where if you want REAL gas - it will be a speciality item. I am told by friends some states dont even have real (pure) gas. Here in Fla you dont know whAT YOU GET I can tell by my milage.60/40 real gas rite now.

handsomerob · 09-21-2007

I don't know jack about euro fuel ratings but tend to follow the wise words of Lemmy (Motorhead) and always use "HIGH OCTANE FUEL, HIGH OCTANE FUEL, HIGH OCTANE FUEL!"

webonnielad · 09-21-2007

But I hear the terms knocking and pinging on here quite a lot. Can anyone explain what these to terms sound like. It'd be handy to know what to listen out for.

Jon (UK)