I'm hesitating!!!

[billwill]

Classic WEAK fuel mixture. Make sure the idle mixture screws are set correctly first before you go looking elsewhere: for DHLA40E Dellorto carburettors set the idle mixture screw(s) 2.1/2 turns out for initial setting, earlier DHLA40 Dellorto carburettors were typically 5.1/2 turns out.

If those are ok but the problem persists then it'll get exciting...

But first record their current settings as I described above.

All good info 45bvtc, but honestly now that he has a colortune transparent spark-plug it is easy to set the idle mixture correctly by seeing the colour of the flame rather than trying to do it by rote counting of turns.

[Elanconvert]

well, guys, here's a thing......took her out this afternoon after seeing to the handbrake [now working! -many thanks to all for the help and info!]
AND NO HESITATION!!!! All I did was clean the plugs, so the question is -
why did I get it before?
Possible causes? PO used Tetraboost, but when I filled up before driving back from Surrey, I just put in neat Shell V-max or whatever it's called [98 octane].
So does Tetraboost sometimes oil/soot up plugs?
Would NOT using Tetraboost lead to fouling of plugs?
I've put in some Millers CVL octane booster this time - anyone use it?
I'd be interested in your opinions!
fred

[types26/36]

I've put in some Millers CVL octane booster this time - anyone use it?
I'd be interested in your opinions!

Yes, I use it in my S2 which has a CR of around 11:1..... if I dont use it then I get pre-ignition (pinking) under acceleration.