Running on three with blue smoke

[SimonSam]

I have recently changed the engine like for like 413 -413 and at first had problems getting it running which turned out to be dodgy dizzy. Anyway it now starts and runs but only on three cylinders despite a spark. The spark plug is a bit wet but doesn't really smell of petrol so thought maybe headgakset but theres no water were it shouldn't be and the system isnt pressurizing. There is a constant blue smoke which isn't horrific but not great. Any ideas? My dad thinks could possible be a dodgy valve? Anyone got any ideas? Seems i'm not havng much luck so far and if this engine has had it then there will be an Samurai up for sale

[Pugsley]

Looks like you need to do a compression test on the dodgy cylinder. You have a spark, you seem to have fuel and I assume you have air - the missing element would appear to be lack of compression.

[SimonSam]

Yep already ordered a compression tester so will do that when it arrives, dreading the result to be honest.

[ScottieJ]

well plue smoke is a sign that your burning oil so yes could be a dodgy/sticking valve with a leaking stem oil seal or it could be the piston rings on that cylinder?

[SimonSam]

Need it to be something simple(ish) or this SJ project of mine could well be very short lived.

[ScottieJ]

the valves are an easy and cheap fix. head off job. the piston rings aren't that bad a job either. What was wrong with the last engine? can you not make a good one out of both?