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912 ULS with 400 hours runs rough at about 3000 rpm. During mag checks, the roughness is fairly pronounced on one ignition and not on the other (runs on either one). The rough side has a 200 rpm drop and the non-rough side has a 100 rpm drop. This persists at 3500 rpm and other values, as well. When the six-pin plugs from the trigger coils to the ignition modules are swapped (B trigger coils to A module and A trigger coils to B module), the roughness changes side (ie, the single ignition switch position that was rough became smooth and the formerly smooth side becomes rough). Given the above, it should be no surprise that swapping the six-pin plugs from the ignition modules to the ignition (high voltage) coils also changed the side of the roughness. Replacing the four trigger coils made no difference. Rebuilding the carburetors made no difference. The resistance tests of the ignition coils were within specification. All eight spark plugs were replaced, no difference. The resistance of the spark plug caps were tested, all were 5K ohms. Any suggestions? Thanks, Fred

My engine has suddenly developed Rough Start-ups but smooths nicely after about 4-5 seconds. I have pulled the prop through as normal prior to each starting and ONE time, It was very difficult to pull it past Top Dead Center... almost like Hydro Lock. . Since it is a 2009 model, I opted for getting the NEWER modules with Soft Start but that did not solve the problem. Any Suggestions? BTW - The older modules will be listed on EBAY in the next few days. My thoughts at this point are... * Stuck Valve *Fouled Plugs due to OIL in the cylinder (Hydro Lock) SEE THE VIDEO CTLS - Electronic ignition module change.mp4

Please send me some contacts to make the Annual Inspection for LSA