Its also just been converted to gas, although I dont think thats the problem.
When I put a bit of a bootful into the car while sitting on about 100km/h, some smoke was visible from behind the car. Hard to tell if it was blue or white because I was looking ahead

Oil is fine, water is fine. Does it sound like the rings or stem seals are gone / going? I was running on lpg at the time so I guess it cant be excessive fuel etc from the carby.
Also its a 22r engine.
Thanks