higher octane fuel

[594rmm]

Have been trying the higher octane fuel in my 1098 would it cause a backfire ? Havent adjusted the mixture
Thanks for any help

[philthehill]

Should not make any difference to the fuel mixture but the higher octane fuel will have different burn characteristics so it would do no harm to alter the ignition very slightly and see what happens.

[594rmm]

Retard it slightly ? Clockwise ?

[philthehill]

Use the micro timing adjustment on the distributer and count how many clicks you turn the knob so you can always go back to where you started.
If I remember correctly the distributer has advance and retard marked on the distributer body by the micro adjustment knob.
Retard first but do not go wild with the retard adjustment - in this case small is beautiful.
If retarding does not cure the problem go back to the start setting and advance slightly again counting the clicks.

[Monty-4]

In theory higher octane fuel should let you advance the timing, if it makes any difference at all, which is unlikely!

[dalebrignall]

i think my engine runs smoother on higher octane fuel

[paul 300358]

I thought turning the distributor clockwise would advance the timing?

[SteveClem]

Mine too.

[SteveClem]

i think my engine runs smoother on higher octane fuel

Mine too

[philthehill]

If there is a need to alter the ignition because higher octane fuel is used the alteration will only be one or two degrees at most so there would be no need to alter or turn the distributer body - just moving the micro adjuster knob will give more than sufficient alteration.