Rotax 912 ULS Engine Vibration Solved
I built a Rans S-20 Raven in 2016 and installed a new 912 ULS engine. 302 hours on the Hobbs. Early this year I started experiencing an engine vibration at cruise power settings. Very Frustrating. Troubleshooting went as follows:
1. Tested with new carbs
2. Tested with new ignition boxes
3. New Prop spinner
4. Dynamically balanced prop.
5..New spark plugs, several times
6. Balanced carbs, several times
7. Repitched prop before dynamic balance
8. Compression check, compression leakdown check
9. New floats
Apparently there have been problems with some gearboxes. I read a post on the yahoo S7 forum that sounded hauntingly familiar. This person even replaced pistons and cylinders troubleshooting this vibration at a considerable expense. His problem went away after he replaced his gearbox. I pulled my gearbox and sent it away to have new gears pressed in. The vibration is now gone! After considerable expense and a great deal of trouble shooting, the problem has been solved. I wanted to share my story in hopes that it might help someone else with similar symptoms.
Rans S20 Raven Built 2016 (Repairman Certificate)
ATP, CFI, II, MEI
2018 Dues Paid