I have a 98 461 with 150 Fitch. Still runs fine. Had it out for first time since last Nov 20 and noticed the water pressure gage was pegging out when running and even at idle it read 25 PSI. It normally ran approx 18-20 and impeller is only 2 yrs old. The tattle tail was shooting plenty of water and it never got hot and ran OK during the day. It has always been garaged. Just not used in last 4 months. Has the gage just gone bad? Or? In addition it is now stuck/hung at approx 25 PSI. As I remember it usually returned to 0 after shutting down.?