Constant misfire ??????

[Bluebird7]

It is worth checking  that the piston travels freely in the dashpot.  I would talk to Burlen on how to carry out a piston drop test for your specific model and what the drop time should be.   Also make sure that the holding down lugs on the dashpot are not damaged in any way as this can resulting the dashpot not sitting down correctly and interfering with correct piston movement.

Not sure SU were ever fitted as standard to Austin 7's, so it's unlikely Burlen could answer the question, but as so many SU's have been retrofitted, what's the best needle for my 1.1/8th dia model possibly ex 803cc Morris ????