(Un)-Scheduled Maintenance

   ~I will say, UL power does a fantastic job of laying out the scheduled maintenance in a way that is easy to follow and understand. However, there are a couple annoying tasks that exist only due to the design of the engine. Instead of going over the tasks clearly marked in the maintenance manual, I will be touching on the items that have come up unexpectedly, not only for myself but as reported by others.


1. Prop flange wear

   ~A former UL Power owner seemed to have the worst of luck with his engine. For some odd reason, his prop flange teeth were wearing down as if they were made of clay. In fact, after changing out his flange 3 times, he finally gave up and just sold the engine. UL Power told him that the prop flange bolt torque was sufficient enough, that the flange teeth weren't needed. But 3 flanges wearing down was just too strange. The cause of this wear is a mystery still. Could his prop flange bolt have been under torqued and loosening? Was it a quality control issue as he believed? I really feel bad for this guy and can't say I've heard anyone else having these flange issues. Either way it's something that can easily be detected during the first 50 hours, as the manual states to re-torque the flange bolt a couple times to ensure is stays put. Why UL Power doesn't use a 1 piece forged crank/flange is beyond me. The technology is there.

See reference: http://www.wingsforum.com/viewtopic.php?f=218&t=23848#p49075



2. ECU Fuel map update (7-4-17)

   ~Back when I first bought my engine, part of the sales agreement was to include a custom ECU fuel map specifically designed to work with my exhaust pipes which I had custom made. This required sending the exhaust off to Belgium for a custom tune. Needless to say, this was the beginning of a huge headache. The first ECU tune came back and the engine was sputtering and stuttering on throttle up. This cause me to have to send my pipes and ECU back to Belgium for a second tune. The second tune came back just as bad as the first, and UL Power would not admit that the tune was a problem. Finally, a 3rd time I sent the pipes and ECU back to Belgium, where they ordered a constant speed prop to simulate my high pitch prop and found the problem to be related to the acceleration values in the mapping. Up until then, almost all UL Power engines were being installed on fairly slow aircraft, so loading the engine with a high fixed pitch prop changed the dynamics of the needed fuel delivery considerably. Still, UL Power blamed "me" for throttling up too quickly and said most pilots never do that. This coming from a company made of race car drivers and not pilots who have never had to go around on landing due to an emergency. We pilots shove the throttle forward quickly all the time. Well, for the last year, the "current" tune on my ECU has been adequate, but no where near perfect. And I can't forget to mention that this special tune they agreed to as part of the sales price did not come free, but ended up costing me in the thousands....ya.
   Here's the fun part. Recently, I've been made aware that this sputtering and stuttering issue was more widespread than thought. So much so, that UL Power decided to update everyone's ECU here in the states to solve the problem. While I'm glad I got to be the squeaky wheel that brought on the updates for all UL Power owners, having to fork over the cash to get mine right shouldn't have happened. Especially after I was told that my custom exhaust really had nothing to do with the issue in the first place, but rather a choice of cruise prop. Either way, I highly recommend to all current and future UL engine owners, to make sure UL Power supplies them with an ECU tune specific to their mission. You don't want to be grounded multiple times, for months on end like I was. Dont' let anyone smooth talk ya into thinking it was an isolated issue. Demand an accurate ECU mapping in writing and good luck!




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