pinking

[moggyadventurer]

Hi,

Is it just me who seems to be struggling to stop my moggy from pinking. I have reset the points and subsequent timing, but still it pinks. I would be grateful of any assistance.

[aupickup]

is it an unleaded head

and you may have to retard more till it stops pinking

[bmcecosse]

Could be due to excessive carbon build up inside the combustion chamber. Some have had success dribbling in redex, or diesel fuel - or even just water while the hot engine is running at a fast idle. beware the smoke screen. Also worth checking the plugs to see what colour they are, Black is too rich - white is too weak - light beige is just right. But essentially - you will need to retard the ignition timing slightly. Best setting is when it's 'not quite' pinking. Do however check if the vacuum advance is working as it should - if it's not working, it's easy to be fooled into setting far too much static advance at idle - which then turns in to far too much advance when running!

[moggyadventurer]

Hi,

I have always timed my mog by static light, and even tried a strobe without much luck.

I decarb the engine 8000 miles ago.

I had heard about the redex idea, maybe blow a few clouds up into the atmosphere - hopefully they wont stop the planes flying!

Thanks for these. I'll try tomorrow and let you know how I get on. When retarding the ignition, any suggestions how many clicks to start by?

[aupickup]

move the whole dizzy anti clockwise to retard
i allways do mine by the sound of the engine never used a strobe or done it statically

then road test and advance till the engine pinks under load then retard slightly

[moggyadventurer]

Hi au,

I'll try my best. Its not unleaded either (forgot to put in my previous reply).

Some smart technician from my local garage suggests it is down to unleaded fuel and octane levels.

Can't really comment to be honest - it did use to run great on lrp mind.

[bmcecosse]

Strobe etc = big waste of time. As Dennis describes - just set it 'by ear' initially - and then listen for the pinking. But do check the vacuum advance is working as it should........... Your mechanic is right - it IS down to octane levels - but is absolutely nothing to do with 'unleaded' - except that it is slightly lower octane than good old 4 Star.