hi to all, i am having severe vibrations with my 912 ULS at startup (just 50 hours used) which sometimes continue to 7 to 8 seconds and then becomes smooth again. during this rough startup, engine speed is about 1000 rpm and when it becomes smooth, it goes back to idle speed that i've set.i have sync'ed it with carb mate. so no synchronization issues after startup. checked spark plugs, carburetors and ignition unit, everything is clear. any advice please??
