Advice on my engine

Hi,

Recently got another Landy after a long time without one. It's a 2.5 petrol series 3 and there's a couple of points that are bugging me.

1) There is a tappet at I can hear chattering away, not always the same loudness and I tried adjusting them but not effect. One of the rockers seemed difficult to get right as I could not get a consistent gap or there seemed to be quite a bit of float. Not sure if the cam is worn or what but never had any difficulty before adjusting tappets. Any ideas?

2) The engine seemed very hesitant and difficult to run while cold. Last night I took off the oil bath air filter to check the oil level and it seemed very full to me. The central tube would be under the oil level so I empted some out and the engine seemed much happier. I assumed perhaps wrongly that drawing air past the oil would be restricting it. My old VW Beetle certainly just has the air bounce of the oil surface rather than bubble the air through the oil. I noticed too that putting my finger over the engine breather hose (which is sucking in air) that the engine squirted out oil onto the garage floor from the front crankshaft seal, not sure if this is normal or not).

Any help would be appreciated, thanks.

2.25 or retrofitted 2.5 , rocker contact surfaces wear as do slides that roller and brass follower run in,if valves arent opening fully crank case can get more pressurised, end of air filter tude should be just above oil level ,it is clearly maked inside the idea been sharp turn air takes lets heavier particles to stick/fall into oil,are you checking valves c;earances using number nine method only turning in clockwise direction not turning back and setting when vale to be fully open has just opened fully and not later if missed go onto next one,sounds like valves arent fully opening

It's a 2.25, no idea on the history of the car but the engine looks suspiciously clean and it's red so I doubt it's the original.

Thanks, I did not notice a mark for the oil level in the filter but the inner tube was about an inch under the surface when opened it.

As for the valves, I found it very awkward to do them tbh as I struggled to turn the engine over. I'll try again, perhaps my method was at fault.

Thanks