I am looking at purchasing another boat to be primarily used on the river for duck hunting and on Lake Ouachita fo fishing. I am pretty well versed on outboards with conventinal props, but other than owning a Jet Ski 15 yrs ago I have no idea about a jet foot motor. I do know about the 15-20 hp difference and kinda how they work but that's about it. Any advice or help would be appreciated! A couple of specific questions I have are: 1. Are parts hard to find for them and are they easy to work on? 2. Are the impellers aluminum or stainless? 3. Are rocks and mud hard on the impellers? 4. Can the pitch be changed? Thanks!