For some background I am installing a Gen 4 Jabiru 3300 in a 750 STOL.  I am using the engine mount cowling and FFW kit from Jabiru USA / Arion Aircraft.  This cowling is the newer version with the square lower opening.  For instructions I have the Jabiru Engine Installation manual from Jabiru in Australia (as available on their website).  I have the Zenith FFW installation manual for Jabiru and the HomeBuilt help video.

I installed the engine to the firewall by fitting the mount to the firewall, removing it and attaching it to the engine usiing the rubber bushings and then mounting the assembly to the aircraft.  This is the method recommended by Pete Krojte and detailed in the video and Zenith manual.  No problem so far and this is the easiest way to proceed.

When I went to fit the cowling there was no way to get the upper cowling to fit properly.  It would fit to the lower cowl when it was off of the airplane and the lower cowl would fit on the airplane, but once the lower cowl was in place there was no way to get the upper cowl to fit the lower cowl.

Upon further careful review the upper rubber engine mounts do not have the aluminum washers installed the same way as the lower mounts. I have attached the drawing from the Jabiru Installation Manual.   JEM3302-8_Inst-%2039.pdf 

Once I removed the engine from the mounts and moved the one washer from the back to the front the engine was tipped up several degrees and now the cowling will fit together.

This one drawing in the Jabiru manual is different from any picture, any other drawing in any other manual and does not even look like a logical way to install the washers. 

I look forward to hearing from anyone else who might have had the same experience and hope to save someone the effort of removing an repositioning the top washers. 

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If you think about this , it makes perfect sense, and I know nothing about jabaru, but have worked with airplanes of all varieties   Tom Hankamp


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