I'm not looking for answers I'm just venting a high level of frustration: I have worked on and built a couple planes, a few cars and a few boats over the years. On all of these I've never struggled like I have tonight installing the oil lines onto the fittings for the oil cooling system. I guess what I'm looking for is why are these particular hoses are used. The other three planes that had a rotax 912 I have either had or have helped build did not use these type oil lines and we never had an issue with standard hoses. There must be a reason I am not aware of.