Sounds like Horizon needs to have a talk with their suppliers or find some new ones that will make the effort to be a little considerate of the end user. When you're delivering products that are inconsistent in there operational methods or fail to work altogether, sooner or later those customers become someone elses.

You can design the best product ever to be brought before the public eye but if it fails to work it becomes instantly useless. Perhaps Horizon needs to start running each of these engines (using the supplied ignition unit) themselves and noting the corrrect voltages and programming for the customer prior to shipping it.