ULPower has done very much "ground testing" and after all these tests, we decided to start with a TBO of "1000 hours".
It is possible that we change the TBO in a later stage, after more experience. However, the determination of an engine's TBO is a serious matter.
Customers who are about to choose an engine often place a lot importance on a high TBO because they think that the maintenance and operational costs of a high TBO engine will be less than an engine with a lower TBO. Many people mistakenly believe that if they buy an engine with a TBO of 800, 1.000 or 1.500 hours, they will have practically no maintenance costs for the duration of the publicized TBO if they operate their engines according to the manufacturer's instructions. They couldn't be more wrong!
Don't be fooled, ask existing users about their experiences with the engine they have installed in their aircraft. You may hear that a few lucky people manage to reach the manufacturer's TBO, but for various reasons (service bulletins and other) most never even get close before their engine has to be maintained or repaired for the first time. It is quite possible that owners of an engine with a "low" TBO have total operating costs which are lower than an owner with a "high" TBO engine of the same power rating!
Also take into consideration how many flying hours you manage to accumulate during a year. It is not just the number of the engine's operational hours which decides when the prescribed maintenance tasks must be performed. Usually the TBO is limited to a certain time frame, for example after 10 years no matter how few hours the engine has been run for. This means even if you fly 50 hours a year, the 10 year limit will mean that your TBO will be due after 500 hours of engine operation. Most users have little to gain from TBO's of more than 500 hours.....
To make a valid comparison between engines of significantly different TBO's, you really need to look at various factors, not just the official TBO.
Remember that in the world of recreational aircraft, an engine's TBO can often just be a perceived selling point advantage that has no more value than the paper on which it is written...