Does anyone know the reason for coil mounting change from plans for UL350is in a Ch750? The engine installation manual from zenith clearly shows coils mounted with the harness plug in the up position, but I believe the mounting plates came predrilled with holes oriented with plug in down position. Home built help also shows plug in down position. The reason for my concern is clearance between wiring harness and cabin heat tubes. I can’t see a logical reason for mounting with harness plug down instead of up. Am I missing something? Thanks , Dean

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Possibly as a preventative measure for avoiding moisture infiltration?

Thanks David, I hadn't  thought of that. I like the idea of having them down for that reason, but my coil  wires come very close to the heat duct where it leaves the muffler box. I will take another look and find a good compromise. I have been looking at your build photos this morning. Nice looking work and a beautiful plane! Your experience and photos are a great resource. I thought I was posting in the UL forum, but It looks like it ended up in the open forum. Will try to figure out why. 


Do not stop looking for a solution, wires rubbing on the heater hose is a real problem. The heat shrink on the my wires was rubbed half off by my heater hose. This was discovered about the same time you posted your question so thanks for pointing this issue out. I utilized zip ties to force a separation, but am not thrilled by this as a long term solution.

Note to all builders, wear from friction of wires, hoses, baffling, and other parts is a very important issue and requires constant vigilance after finishing a careful build. Zip ties are a great organizing tool keeping in mind that a loose zip tie rubbing on steel tubing can wear the metal. 


404 hours on the Hobbs and still grinning!

Ralph, Glad you found your wire issue before it became a real problem. I am able to tie my hoses back with a zip tie, but reluctant to do so because if tie breaks, wire in hose will make it spring right into wires. If I don't relocate coils, Adel clamps will secure hoses. Even if it looks good in a static state, things tend to move more than a guy thinks when running under a load. 

Hum.. Do I have my installed upside down?

Tim, not so sure it really matters to be honest.  I have mine as yours is depicted. Having the connector on top makes it easier to connect/disconnect versus squatting and looking up trying to do so.


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