I am having RPM isues w/ my 07' 250 on a Z21. I cannot get the RPM's past 5500, changed the prop 25M, 23M and it still cannot get past 5500. I have a 21M coming so I can completely rule out a prop issue. I am in Colorado so the high altitude requires a lower pitch here. I have heard it could be some clogging of a filter in the VST tank... Anyway, I want to troubleshoot before I have to pay someone to do it. It has been plugged in for a diagnostic and it reached 5900 RPM very early on. Motor has 43 or so hrs on it. Any advice will be appreciated, thanks.