77 Evinrude 115 hp won't go faster than 20 mph

[oldboat1]

yessir. address current issues (incl potential ones). Something seems to have changed....

 

[Ktgritz]

Nearly identical 110-115 the more I watch the video more I think lower unit

 

[interalian]

Since you get a massive rooster tail when trying to go faster, something HAS to be disturbing the waterflow under the boat and taking water away from the prop. If the prop was slipping, you'd get revs but no rooster tail. If the shift dogs were jumping, the motor would bang back into gear which we're not seeing.

Can you look over the stern to see what it's doing while somebody else pilots?

EDIT: is the hull bottom secure? One time years ago, my dad smoothed some silicone out forward of the transom of our boat to ease the water going over a depth sounder. The silicone peeled away from the hull and scooped water away from the motor at high speeds.

 

[Ktgritz]

I'm going to cut that plate up a little raise the motor to recommended height and put my other prop on. This is so frustrating

 

[Ktgritz]

You watched the new video I posted? There is a small bead of silicone but it's flush with the bottom

 

[interalian]

Yes, but it's hard to tell what's happening there. I was expecting to see the water being pushed away from the prop, but it seems more like the water is being disturbed before it gets to the prop. Any lips or ledges that protrude at the transom line can disturb the water there.

 

[Ktgritz]

If I cut 1/2 inch off of that there will be nothing but the hull which is hard to tell in the picture but it's in good shape

 

[interalian]

In post #33 you linked a YouTube clip the prior owner made where the boat was running fast. Was the diamond plate on then? Did he add it or did you?

 

[oldboat1]

^^and if added, why?

 

[trailking82]

When i looked at the picture from the rear, it apears there is something further ahead under the hull. Is there something attached under the hull?

 

[ondarvr]

When i looked at the picture from the rear, it apears there is something further ahead under the hull. Is there something attached under the hull?

Looks like the keel to me.

 

[Ktgritz]

It was on there

 

[interalian]

No Title

This screenshot from your 'transom view' clip seems to show aerated waterflow just next to the skeg.

 

[Ktgritz]

Skeg has a couple dings...

 

[ondarvr]

Dings, nicks and gouges don't make much of a difference, bent and crooked can.

 

[Ktgritz]

No Title

Like this? Lol if I thought it was that important I would have said something

 

[ondarvr]

Sometimes it makes a difference, other times not, but this may be the time it does.

​They tend to break if you try to straighten them, but it's there to protect the prop, people frequently don't replace them when they break off, it just looks bad. So it's up to you, and you may get some good options from others here.

 

[Ktgritz]

What I'm hearing is it's worth a shot

 

[ondarvr]

The curve to the side doesn't matter that much, the issue would be from it being bent a bit sideways too. So look at it from front to back and see if it's straight that way.

 

[Ktgritz]

That pic is in line with the prop shaft