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My CH750 is powered by the Rotax 912S engine. To date I have 90 trouble free hours on the engine with no adjustments required other than tightening a radiator hose clamp. While flying the other day the engine oil pressure started to fluctuate and go full scale both directions on the D180. This really gets your attention! I selected a field for a forced landing, but after flying the approach with Rotax humming along happily (all oil temps & cylinder temps normal) I reasoned I was risking more damage to my CH750 than remaining airborne with a running engine... my home airfield was only 10 minutes away. It was an anxious, but uneventful flight home. I doubt the Rotax 912 would continue running much longer than a minute or two with zero oil pressure. My Rotax 912S has a 2000 hrs TBO, and a new style Honeywell electronic oil pressure sender that replaced the standard Rotax VDO sender used previously.
The Honeywell sender is $400 vs. the VDO sender $45 that Rotax previously used. Bob Robertson of Light Engine Services (Rotax @ Salmon Arm B.C.) sent me a new Aviasport oil pressure guage to wire in as the Honeywell sender (and guage) requires a 12 volt supply to work. By installing this "stand alone" oil pressure guage I was able to prove the Honeywell sender was defective... and not my Dynon D180 as suggested by Rotax. The Honeywell sender is being replaced by Rotax under warranty, and Rotax maintains they have never had a history of failure. In the future if the Honeywell sender fails again (not under warranty) I will replace it with the older VDO sender. It is then a simple change in the Dynon D180 setup menu to select the VDO sender and your back in business. Note :The Rotax 912 in my CH601HD has the older VDO sender..... and 1200 hrs with no trouble.