very rough idle
My 912 ULS is a 2001 vintage but only has 2 hours run time on it, all within the last month. It initially started and ran smooth for the first 2 hours and then started leaking gas out of the vent lines and idling rough. During that time I checked the fuel pressure while running and it varied between 6-8 psi (rising at higher rpm) with a steady reading (no spiking of the reading high or low). As a result, I put a level 3 service kit into the carbs and that seemed to fix the vent leaks for a short while but now the engine has become harder to start and once it does start it shakes violently at idle and it seems that the shaking causes gas to leak out of the right side carb vent tube again (but not the left side). The carb floats were not replaced because they all are floating at the level they should be at in both carbs. When I pull the plugs and turn over the engine to see if there is spark across the plug gaps there is spark at each plug but it appears weaker on the #1 and #4 plugs. As the engine turns over and I pull each spark plug slightly away from the engine block where it is temporarily grounded the stronger plugs will produce a longer spark but not the "weaker" appearing ones. Is there something more I can do or check to discover what may be the cause of the rough idle?