
Was running sweet until I started it to get to work, ran rough and sounded like it wasnt firing on all 4. Overdue a service and in the hope of curing the problem with some basics have done valves, cleaned air filter etc. Still running bad, cylinders 1 and 4 dont seem to be firing and headers are cold, so have tested the relevant coil (primary and secondary - both within tolerances), got sparks on all 4 though I'm not sure the spark is great, switched round plugs and ran the same, was running iridium so switched back to standard and replaced and all 4, started up and ran super sweet again. Problem solved I thought..... for a 1 minute or so, and then back again to the same problem.
Makes me think its a carb issue...i.e. 1 and 4 getting flooded or starved. Any thoughts greatly appreciated!

cheers