How much gap between trim-tab and prop

[Plainsman]

How much space do I need between the trim-tab and the blades of the prop. I received my new prop, a 17in pitch with a 13 1/4 dia. I put it on and looking at it there is about an 1/8in space from the blade to the trim-tab. Seems to close for me, am I correct?

The prop I am replacing is not as long as the new one. The original is 5 1/2in long, 19in pitch 13 1/4 dia whereas the new one is 6 1/2 in long 17in pitch with a 13 1/4 dia.

Original prop # is 48-65024A1 19in pitch.

I am thinking in need to send this new back, but how can I be sure I get a replacement of the correct length?

Thanks
Eric

 

[WillyBWright]

Re: How much gap between trim-tab and prop

Notch the tab for additional clearance. I've done it to quite a few boats with no complaints. Just make the leading edge of the notch pointy like the rest. You might also be able to find a trim tab that's offset to the back by an inch or so, depending on the make of the motor.

 

[mole2]

Re: How much gap between trim-tab and prop

You could try something like this to get the clearance you need. There are also others.

Mercury Marine 3.0L Trim Tab

 

[Bondo]

Re: How much gap between trim-tab and prop

Just Grind it out alittle,......

1/8th" is just alittle Tight,......... 1/4" is More than Enough.........

 

[Plainsman]

Re: How much gap between trim-tab and prop

Thanks guys!

 

[jimmbo]

Re: How much gap between trim-tab and prop

Is your old prop pre 1979? the post 78 props had more rake, which would bring the blade tip further back, and all were pretty much cupped. The pre 79 props had a different blade shape, shorter hub, and most weren't cupped.

 

[Plainsman]

Re: How much gap between trim-tab and prop

Is your old prop pre 1979? the post 78 props had more rake, which would bring the blade tip further back, and all were pretty much cupped. The pre 79 props had a different blade shape, shorter hub, and most weren't cupped.

I am not sure, it came with the boat. I ground down the tab to give me about 3/8" clearance.

Thanks to all!