I have the same boat and motor and had the speedometer issue and recently the hose came off the idle control valve from putting my engine up all the time to protect that delicate aluminum propeller.

Thx I have Mariner 50hp 4 stroke, that is the same. Tomorrow I chek that fix. Greethings from Croatia.

Thanks for making your videos. I have the same motor and this helps alot.

Brand new pontoon boat with 60 HP Mercury no speedo, at least I have my Lowrance. I will check this and the hose in the morning

Thanks for the tip.