‘91 merc 60hp hitting wot rpm??

[Evinrudej]

Hi all so last weekend I took my 16ft deep v aluminum boat with a 60hp mercury 2 stroke 1991 out on the water. With a full tank of gas and two people boat was hitting 33mph according to my gps on my phone and the rpm gauge was reading 4500rpm at wot. If I’m correct rpm range should be 5000-5500 for this model? Could the gauge be off??

 

[jimmbo]

Maybe, or you are about 4" or so, Over-Propped
What Pitch is your Prop?
Is this boat and motor, new to you, or have you had it several Yrs? If you have had it for a while, what was the performance like last year?

 

[Evinrudej]

Yes it’s newish to me. Had it about a year now and last season was the same result. Prop is a 13p prop stainless prop. Was thinking about dropping down to an 11p??

 

[jimmbo]

Before you go spending any money on Props, what condition is the Engine in? Have you done a Compression Test? If yes, what are the Numbers?
Is the Spark strong enough to jump a 3/8" Gap?
Is the Tach set correctly? Which for an Alternator driven Tach should be 6P