I've recently heard that standard 91 octane fuel will be phased out to be replaced fully by an ethanol blend within 6 months or thereabouts, so the lowest octane non ethanol blend available will be 95.

Given that our bikes, well at least mine at least, tends to run rather shite with anything other than 91, and with just about every mechanic I've ever spoken to saying to avoid ethanol - what are the options???

Been thinking zackly the same thing as my old 750, just like all of the old carbed Monsters that I've heard of just wont run on the higher octane fuel.

Maybe I should stock up on spark plugs. 

I'd like to hear from the boffins here as to just what we might be able to do to keep these oldies on the road where they should be!

Just what is it that makes these motors so cranky on the higher octanes?? Ignition system need upgrade?? Raise in compression maybe?? Ignition timing??  Cams?? 

Quote from: dragonworld on August 22, 2010, 03:58:02 AM
I'd like to hear from the boffins here as to just what we might be able to do to keep these oldies on the road where they should be!

Its not just the older carb bikes. I think most of the smaller capacities (at least) run better on the 91.

Quote from: dragonworld on August 22, 2010, 03:58:02 AM
Just what is it that makes these motors so cranky on the higher octanes?? Ignition system need upgrade?? Raise in compression maybe?? Ignition timing??  Cams?? 

What abour air intake? Is that likely to make any difference?

I'm totally guessing here, as I haven't tried any of these things.

My plan of attack should I experience problems with the 95 octane fuel is:

• Replace the stock ignition wires with lower resistance ones, to get a better spark and ensure consistent firing
• Increase the plug gap a little over standard, to get better fuel ignition
• Try expensive iridium spark plugs (DCPR8EIX), with a slightly bigger than standard gap
• Try running hotter plugs (DCPR7EIX)
  
• Replace the coils, with ones that provide a better spark, then open the plug gap out a little more

Mine runs great on 95 
put some in last night and she is purring

Quote from: dezmonster on August 22, 2010, 12:53:08 PM
Mine runs great on 95 
put some in last night and she is purring

So does mine and on 98

My 1000DS will run on anything but best on 95 with no discernable advantage from the top drop.

But the 750 even with the Iridiums doesnt cope with the higher octane. 

A change to a more potent ignition system would be on the right track but I think it might go a bit further than that!?

As far as I know the 800 runs fine on 91 or 95.

We always used to put 95 in the 620 as well ... it seemed to run fine, but the pros didn't like the effect on the plugs (I can't remember exactly but think dark and oily was the prognosis). So we have been running 91 where possible. Still seems to run fine.

As a mechanical numpty, I have no idea ... so how far out is my query about the intake? I thought the symptoms we had were caused by a more dense fuel (with the higher octane) and was hoping more air might help to provide a better mixture. I was sure we were told that the 95 was providing too rich of a mixture hence the plug concern.

Educate me peoples

I run either 95 or 98 and she is sweet as.

Got the full open air box and it didnt change the outcome as far as low octane swill as compared to the higher octane.

Standard air box, standard air box with K&N filter and open air box with K&N equals the same result!  [moto]

750 that is! 

You can advance the ignition timing on the higher octain fuels to get you bikr to run better.

Maybe other points are that:

1. This will force people to pay more for the higher octane fuels cos their vehicle manufacturer does not endorse the use of the "E" fuel.

2. And is a way to attempt to get more of the older vehicles off trhe road??

(Yes, I am a conspiracy theorist, and there is ALWAYS an ulterior motive to anything Guvmints,  , environmentalists do! For our own good of course! )

Got told at Gowanlochs , the higher the octane the hotter they run . So mid summer" probly not a good idea for 98 

I love conspiracy theories Dragon.

What I think about the E10:
. incentives were offered under environmental grounds as a renewable fuel source
. E10 offered for sale at a slight discount
. people prefer the cheaper E10 even though their increased fuel consumption is actually costing them more
. market (for non-E10) dwindles due to huge uptake in E10 and no incentive from the fuel companies because they make more money by selling more fuel
. fuel suppliers realise the impost of stocking so many different fuel types
. fuel suppliers lobby the authorities to enforce E10 citing environmental consideration and cost savings to the consumer
. government legislates on E10
. predominantly ignorant public don't give a shit because E10 is cheaper and cars are disposable and not worth maintaining.

Everybody is happy ... unless you have a small capacity Ducati, but even worse if you have a small capacity Ducati with a plastic tank.

What's to bet now that Bob Katter has way too much power that they'll be putting ethanol into all fuel.