Zenith Aircraft Builders and Flyers
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15 hour maint checklist
UL 350 iS Herman advised me to check all six head bolts on each cylinder ; turned out to be good advice !! fuel pressure is a little higher with both pumps running at same time ; the banjo fittings on the fuel pumps seeped at the higher pressure ( both pumps on ) any body else dislike the banjo fittings ?
Replies to This Discussion
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Permalink Reply by Jim MacWilliams
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Craig, is there more to this story? Why did Herman advise checking the six head bolts? I just checked ULPower service bulletins and there is no such advice there. Were you having some issue?
WRT the banjo fittings on the fuel pumps, I have not had any problems with them, but I did just replace the hoses feeding the fuel pumps - they were overdue for replacement.
What kind of fuel pressures are you reading?
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Herman did not state a specific reason , I was already thinking that if it was important to check the torque on the four easy to get to head bolts then they all needed checked , therefore his encouragement sealed the deal . Fuel pressure in flight 51 psi ? in the middle of the green bar on Dynon as prescribed by UL Power
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So, I'm looking at the UL Power operations manual (revision 8). I have the 350i, but the two graphs covering both the naturally aspirated engine (mine) and the turbo engines (yours) are side by side (page 13). They show the recommended fuel pressure as a function of engine rpm. Both graphs show no more than 49psi at max rpm, so I don't understand where you see 51 psi in the middle of the green on the Dynon unless the limits set in the Dynon are not matching what UL Power's operation manual states (35 to 49 psi). Are you running both fuel pumps all the time?
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I have the 130 horse engine that is N/A , I thought my model is UL 350iS ( will double check ) running only the ECM controlled pump on normal operations . The color parameters that I put in the Dynon were based on UL info , next time I go up I will check the psi & other readings . The higher psi was with engine off & both pumps on . As for banjo fittings : when I leak checked after fuel filters replacement the banjo's seeped at the slightly higher pressure of both pumps but remained dry at the lower pressure. Could be wrong about any of this but will double check & post what I find out
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