Running Issue

[Scripto87]

Im 100% new here and fairly new to boats. I picked up a 1991 Maxum 2100sc 5.0 and am having a weird issue. Also side note I been an auto tech for 15+ years so I have one throuh the basics. I will happily recheck them if need be to get this girl going right.
So it runs and starts all the time except when she doesn't. If I keep the prop down button depressed while starting her and hold it she will run during the times she normally won't. I had it on the lake yesterday started ran fine for 5 times but on the last one drifted across the lake and would not start and run unless I held the prop down but on the throttle control down. It would run and rev in neutral but would not stay running in actual "drive" unless that button was pressed. Thoughts..things to check? I appreciate all the help and will get some pics of her up soon. Thanks for any and all advice and tips

[mmwjr]

I have no clue why holding the trim down switch would keep your engine running as the wiring for the trim pump is completely separate from the engine wiring. Is this only happening when the engine is cold and goes away once it reach normal operating temperature? If so very the choke is operating properly. Also you say in neutral you don’t have any issues with it stalling. Do you have an Alpha outdrive? If yes are you shifting quickly into gear? A slow shift may cause the shift interrupt switch to engage and kill the engine.

[donald]

I had this happen to me on an older boat, sounds like the shift cable needs to be adjusted or replaced.
I had to replace my lower shift cable last year for the same problem.
Don