Question about Sunbird Spirit 170 OB

[flyingcamelape]

HI, I own a '96 Sunbird Spirit 170 OB with a johnson spl 112hp. I was wondering what others with this boat or similar boats were getting. I get 43mph max with perfect conditions which seems kind of slow considering the boat was rated at that speed with a 88hp.

 

[quantumleap]

Re: Question about Sunbird Spirit 170 OB

43 MPH for that combo sounds about right. What are the rpm's at wot. You need to be propped where you are running at the upper end of the recommended rpm range at wot. Also make sure the motor is mounted at the proper height(cav. plate even with or slightly higher than the bottom of the keel). Also check speedo with GPS. Dash speedos are often incorrect, but as I said, it sounds about right to me.

 

[flyingcamelape]

Re: Question about Sunbird Spirit 170 OB

Im running at about 5200 with a stainless steel prop(13.125x17). When we had the original aluminum prop on it it ran at 5400+(13.75x17).