Last week my CFI was giving me a practice checkride. We were about 4500 msl, when I did a power off stall, during which the engine started to shake! This was at approx. 3500 rpm. The engine ran smooth at higher RPM. We headed back to the airport ASAP, We came in pretty steep, instructor wanted to keep as much altitude as possible. On final I had to pull pretty hard on throttle to get it to go to idle. We finally just turned the engine off about 25 feet off the ground because of the shaking. I restarted the engine after touch down to taxi back to the hanger. I got it started and we both smelled fuel, not wanting to damage anything else we did the walk of shame and pull the bird the last 750 ft. I took the engine cover off and started looking over things and noticed that the throttle cable Nut came loose on the right carb. This would be the point of attachment to where the cable attaches to the carb. This allowed full throttle but not idle, so the two carbs were fighting each other. This caused my shaking!! I adjusted the cables back to factory spec and re locked them together! I also changed spark plugs since I smelled fuel and was guessing we fouled them. Tonight I did a few hops down the 5900 ft runway then after being pleased with that I did a few touch and go s . Upon final approach around 3000 I had alittle vibration again! We re synced the carbs after adjusting the cable, so I'm wondering if there is something I might have missed??? It runs perfect otherwise!!

Thanks
Patrick
Series 6 - rotax 912 100 hp
trigear