1991 Mercury XR4 2.4L idling very high

[Gray2.4L]

So I have a 1991 Mercury XR4 serial # ODO38009. So following some advice I was given to start up and run my motor every couple of weeks when not in use to clear all the junk out and let new gas/oil go through everything to keep it running good. Well yesterday I started it up for the first time in 6 weeks or so and as expected it took a while to get started, but once it got going ran good. I have no plans to winterize it (hoping lakes don’t freeze over this winter) so want to keep it running good year round. Anyway once I got it started there was lots of smoke (normal) but then it the idle rpms kept creeping up to around 2000 and stayed there. When I would turn it off and start it up again it would start in the low 1000’s (1000-1200) then almost immediately jump back up to 2000. Is the timing off or something? I had the idle stabilizer box removed and idle manually set to 800ish rpms. Over the summer it would idle at about 800 when warm, sometimes 900 or 1000 but mainly 800. Yesterday it was on a hose so I know that can make a difference but surely not 1000+ difference right? Can the timing just go out of whack like that? Last time I had it on the lake it ran 52 at 5500-5600 rpms trimmed out (by myself it would do 5800 before jackplate at 57-58mph) not that it means much but why would the idle be affected so much recently? Jumping from 800 to 2000 in a few months has me a little concerned. Thanks for the help guys

[EuropeanAM]

Timing does not change without something being altered (unless you have a bias-circuit problem in the switchboxes).

Make sure that it's either in neutral OR in gear, and not perhaps "hung" between the two due to cold cables/control/hardened grease in the shift slide.