5500 RPM Mean Motor Running Well?

[Rhadley]

115 HP Johnson, 1978, on tri-hull 17' Glastron. I get 5500 rpm, but top speed is only about 32mph. Does the fact that it runs smoothly at 5500 rpm mean all is well with the motor? I realize top speed is also determined by the boat shape, weight, etc., but it seems too slow.

 

[MurdockJr]

Re: 5500 RPM Mean Motor Running Well?

Is that speed from the boat speedo or gps??

 

[Rhadley]

Re: 5500 RPM Mean Motor Running Well?

That is indicated speed on the boat dash.

 

[TopNotch]

Re: 5500 RPM Mean Motor Running Well?

Sounds pretty accurate to me, my friend has a 17' modified-vee hull with a 115hp on the back. Does 33-34mph (gps) with a good load. Lightened up, in smooth water, might do 36mph...<br /><br />So id say your pretty close to max speed. A slick bottom, stainless prop, trimmed out right and you could squeeze out alittle more....