1976 Evinrude 15Hp Long shaft w/ poor reverse power

[dsta]

The subject motor is mounted on a 23' trailer sailer. In forward it pushes the boat along at hull speed with about 3/4 throttle. In reverse it has always been pathetic--barely able to stop the boat from slow speed or hold the boat against a moderate breeze. My father thinks that the problem is due to the thru prop exhaust and recalls seeing exhaust re-routing kits to solve the problem years ago. In searching the web and this forum I've found no mention of such kits.<br />1. Do this group's experts concur on the diagnosis?<br />2. Any suggestions for a solution?

 

[Fouled Plug]

Re: 1976 Evinrude 15Hp Long shaft w/ poor reverse power

Are you getting a lot of prop wash on the transom? It could be the prop does not sit far enough under the hull to be effective in reverse.

 

[dsta]

Re: 1976 Evinrude 15Hp Long shaft w/ poor reverse power

The prop is well clear of the transom.

 

[buttonhook]

Re: 1976 Evinrude 15Hp Long shaft w/ poor reverse power

you may have the wrong type of prop on it. some prop don't work as well in rev. due to design.<br />does it look like mouse ears or does it have alot a screw to it(looks like knives)?

 

[dsta]

Re: 1976 Evinrude 15Hp Long shaft w/ poor reverse power

It is a three bladed prop with a fair amount of pitch to it.

 

[Yepblaze]

Re: 1976 Evinrude 15Hp Long shaft w/ poor reverse power

For thrust you want diameter. Pitch is OK but cupping might not be advantagous to backing.<br /><br />Worn or out of adjustment throttle components in the link and sync apparatus could cause less than desired power at a particular throttle setting.(full reverse throttle)<br /><br />Perhaps all you need do is a little precision grinding carefully done on the "throttle in reverse stop", so as to allow more backing throttle.

 

[Hooty]

Re: 1976 Evinrude 15Hp Long shaft w/ poor reverse power

Look at "Outboard Exhaust Housing". I don't know if they make one for that engine or not.<br />I suspect that the configuration of your boat and the size of the engine has more to do with it then anything though.<br /><br /> Bob's Machine <br /><br />c/6<br /><br />Hooty

 

[buttonhook]

Re: 1976 Evinrude 15Hp Long shaft w/ poor reverse power

dsta,<br /><br />pitch is not what I'm talking about they make props to deal with the exhaust gases in the prop. they have a different shape. blade than the original. the are made for workboats. boats that need to manuv. just as good in rev as in forward. if you look at them straight on, the blades look fat and round like 3 mickey mouse ears at disney world. the OMC prop looks more like an electric. trolling motor blade(weedless)the blades are smaller and more laid back.<br />you need to talk to a good prop shop an tell them you need a prop that is just as good in rev. as in forw.