Why was the motor raised? Should I lower it?

[motorcyclepilot]

This is a 1968 Starcraft aluminum boat with an Evinrude v4 100hp...1991 or so. I think it's a 20" shaft and the transom on the boat is about 21", but the PO raised the engine about 3". Feels like it cavitates too easily when trimming out and turning. Not sure where the engine "should" be mounted. Thoughts? Thank you.

 

[Scott Danforth]

Lower the motor, stand back about 15 feet and take a pic perpendicular to the keel swowing the keel and anticav plate

The pics you took dont show the location og the keel and anticav plate

 

[ThomW]

Scott's 100% right. The pictures you posted show the mounting area, which is raised up 3 inches, however, all that will matter to determine correct height is where the anti-cavitation plate on lower unit is in comparison to the bottom keel of your boat when the motor is trimmed down. Lower the motor, stand back, and take a picture from behind showing where the plate is in comparison to bottom of your boat.

 

[motorcyclepilot]

Not the best pictures of what I think you mean, but my eyes show the cav plate in a plane a few inches above the bottom of the boat.

Thanks.

 

[tramsdell]

Probably after the PO smashed the skeg, they thought raising the motor would prevent such mishaps in the future. Put it back on the other mount holes and it out to be real close to right, then get the skeg repaired or theres a company that makes bolt on skeg guards that they claim dont need much remaining skeg to mount

 

[Scott Danforth]

got a view from the side perpendicular to the keel and parallel with the transom. these obtuse angle shots do not show enough.

 

[robert graham]

Maybe the previous owner should have invested in a hydraulic Jack plate so he could adjust up and down, as needed....

 

[motorcyclepilot]

Sooo.... took to the local boat shop and they agreed that the motor was mounted too high and if they could correct it for me. Will let you all know how things go afterwards.

 

[jimmbo]

'Too High' will vary depending on what prop is chosen, and how much Ventilation on acceleration you are willing to put up with, and how closely you monitor the engine for signs of Overheating

As implied, from where and what angles photos are taken, can cause a false interpretation of where the AV plate is in relation to the hul

 

[Sea Rider]

Post a side pic of both lower leg plates whith motor sitting fully vertical down. The good issue is that there's lots of transom heights to play with without the need to chop or raise transom.

Test combo at wot on flat, calm water cond with trim set at 90 deg, deck weight must be evenly distributed, report if having prop aeration at straight water courses and at close tight turns at plane. If so, much be worse at choppy, windy conditions if motor sits too high on transom.

Happy Boating