1980-1983 Johnson seahorse 7.5 HP Prop Question

Tman · Mar 28, 2017

Hi all,
I purchased a 7.5 Johnson in the middle of summer last year, from the day i bought it i always thought the prop looks like the blades were almost flattened out with the tips of the blades almost pointing to the transom of the boat. is this normal? Shouldn't the tips of the blades be the further away than the rest of the blade? i believe its a 8.5" x 9 pin Drive.

thank you,

WALI4VR · Mar 28, 2017

Don't know why but that's the way they're made.

Sent from my XT1650 using Tapatalk

NautiBuoys · Mar 28, 2017

It could be the angle of the photo, but I suspect your concern is warranted. A quick test is to take off prop and on flat ground using a level, check blade tip to tip all are equal level. Then measure from ground up to each blade tip that all are equal. There could be other issues we can't see but that will give you a rough idea if new prop or rebuild in order.

DaleH · Mar 28, 2017

I may have a spare prop just like that one at home, as I know it is an old OMC pin drive from the smaller motors.

My best guess would be that someone may have been using the motor to push a heavy load and modified the prop to a lower pitch (albeit via the 'Bubba' method ...) to get the RPMs up, so they weren't lugging the motor.

Tman · Mar 28, 2017

DaleH said:
I may have a spare prop just like that one at home, as I know it is an old OMC pin drive from the smaller motors.

My best guess would be that someone may have been using the motor to push a heavy load and modified the prop to a lower pitch (albeit via the 'Bubba' method ...) to get the RPMs up, so they weren't lugging the motor.

Ill take some measurements of mine tonight and post them. Do you mind taking some measurements of yours and we can compare?

Pappy · Mar 29, 2017

Guys....that is what they look like. That prop is a carry over from the 40s and 50s. They look flat, almost bent backward right out of the box.

Tman · Mar 29, 2017

do I have any other options for props? something with a little higher pitch to get more speed?

1980-1983 Johnson seahorse 7.5 HP Prop Question

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