by SonexN76ET » Mon Oct 27, 2014 9:29 pm
I tried two filters. One was an Earl's Performance Plumbing (a division of of Holly) 85 micron that had a filter screen. This one worked great. The only problem was it is too long for my setup and I worried about my braided flexible fuel line being too short and not having enough flex to absorb vibration. I will likely go back to this one after I make some minor firewall reconfiguration to accommodate the longer filter. The filter body itself is not so long, only about 2.6 inches, but it has two male 06AN ends on it and I needed to use a coupler to mount it to the bulkhead fuel fitting.
The next one I tried was a JEGS 40 micron filter that had a female 06AN end and a male 06AN end. This one fit my configuration perfectly. However, the fuel pressure dropped way low! I did not bother to check the fuel flow with this filter before I test flew it and my EGT and CHT temps went to the redline and my engine acted like it would only go to 3/4 power. I think this filter might be meant only for fuel injected engines or carbureted engines with fuel pumps. So be careful what filter you select.
From my experience it would seem the ones with the filter screen of 85 microns or so work best for gravity fed fuel systems in the Sonex.
After I took the JEGS 40 micron filter off, I took out and cleaned the fuel tank finger screen, made all new fuel lines, put in a new air filter, and flushed out my AeroInjector to make sure nothing else may have been restricting my fuel flow. It turns out the JEGS filter was too restrictive.
I am temporarily flying without a fuel filter until I can get my firewall properly configured to handle the Earl's 85 Micron Filter.
Sonex Tri Gear, Rotax 912 ULS, Sensenich 3 Blade Ground Adjustable Propeller
MGL Velocity EMS, Garmin GTR 200 Comm, GTX 335 ADS B Out Transponder
ILevil AW AHRS & ADS-B In, UAvionix AV20S
200+ hours previously with Aerovee engine
Sarasota, Florida