2.25 petrol engine

Hi all , just bought a non runner series 3 been running on LPG at some point . I did manage to get it to run on full chocke but won't rev without back firing . I'm assuming that valve wear has occurred due to LPG and gases passing into manifolds ?? It's been fitted with electronic iginition and all electrics look healthy .
Any ideas or anyone with a 2.25 engine for sale ?
Cheers

Might be just a dirty carb. Have you cleaned the idler jet? Backfire under acceleration often caused by that. If you've got the money I'd consider sending it to Turner. Engineering for a refurb. Check their website. Apart from that personally I'd do away with the electronic ignition. It's an engine from the 1960s and likely to run better if set up with conventional ignition.

Thanks for reply I've changed the carb but still the same issue . I think the head will have to come off or replace with a good unit .

Turner will do that for you. I got my head done by thm a few years ago.