1983 mercury 115 tower max rpm

[bcboy13]

Hey there I have a 1983 tower of power 115 and was wondering what the max rpm for this motor is. I'm pulling about 5300 rpm with a 21p quicksilver SS prop. It's on a glastron 16.6 cvx. The reason I ask is I'm not getting max speed out of it, only about 45mph. Any thoughts?

 

[XS]

Re: 1983 mercury 115 tower max rpm

5600. you can push it to 5800

 

[Charlie61]

Re: 1983 mercury 115 tower max rpm

you are not going to run it full all the time I hope but 45mph is not to bad I have the same engine but I just fish

 

[Chris1956]

Re: 1983 mercury 115 tower max rpm

Ar you using GPS to determine your speed? Normally a 21" pitch prop will give aproximately 53MPH at 5300, 35 MPH at 3500RPM, whne trimmed out properly..... Do you have the motor trimmed out? Trimming is where you will gain the most speed.

 

[bcboy13]

Re: 1983 mercury 115 tower max rpm

Yes this is gps speed. I'll play With the trimming and see. What else could rob speed if I'm pulling max rpm?

 

[Dave1027]

Re: 1983 mercury 115 tower max rpm

Yes this is gps speed. I'll play With the trimming and see. What else could rob speed if I'm pulling max rpm?

Heavy boat or heavy load in boat.