Spark plugs were changed first.
Removed tank, no obvious issues.
Removed carbs to see what has been done. Someone has been inside as there are scratch marks in the bowls.
Rubbers to the manifold, have a few cracks. But nothing seems to be right through. Like was suggested they would be ok on here
Carbs 4 and 3 seperated, just awaiting ultrasonic cleaning fluid. Then I shall do each carb one at a time.
I think, but I need to confirm, that three of the four pilot jets are blocked.
No carburettor expert here. But I'm lead to believe they are the issue for idling.