Not versed very well on engine props. If I cut the other two props to match the broken one will I still have enough thrust to push a 12’ Jon boat? 5 horse engine.

On a larger outboard, I would not do it. On a 5 hp, you may be ok, but I don’t know. I’d opt for a new propeller or get it repaired!

New prop or repair; whichever is cheaper.

What about adding weight to the broken fin till it stops vibrating?(it’s out of balance)

I know you are looking for the least expensive way but a repair or new prop is what needs to be done. Cut those others off and try it if it works I would keep it as a spare only.

That vibration will damage the motor and then it will really cost you.

Marine outfitters sell composite props pretty reasonably. I have replaced many props due to damage done on the Mississippi here in Iowa. On my larger outboards I lean towards stainless steel but on my jon boat with a small outboard I use composite because they last longer due to taking the abuse of striking underwater logs/rocks than the cast aluminum types. I wouldn't mess with your prop for what a composite replacement cost.

Among other things, you will over-rev the engine. Get a new prop.

Thanks all!

Little Merc? Yeah, I think I would. Would bring the prop back in balance. The props on my river boat live in gravel rivers and get ground down a lot.
Look on EBay. They always have a good selection of props on there. I've got two types of props. The good ones for when the river is up with plenty of depth in the spring and the not so good ones like what you have pictured; for when the river is down in the summer. What you have pictured looks better than some of the stuff I run. I've always heard that it's always better to over rev a boat motor a little bit than to under rev (bog it down) it.

For years Michigan Wheel made good quality American propellers. They've went the way of everyone else and have outsourced their product to China. I bought one, was total crap and I sent it back.

Look on EBay, you'll find one on there. Gonna run on the river you need a spare prop anyway.

No, you don't want to over rev an outboard..of any size, lugging is bad too, that's why they sell different sizes, to keep you in the sweet spot...

Chuck that prop as scrap and get another one of the same size, if that one worked well. A prop repair is possible but will probably be close to the cost of new, and the prop guy may just, probably, say it's not worth it...

save money on something else.

Itd be hard to balance. You could spin it on a screwdriver or something to try to balance it but even then you wouldn't be too sure. Probably a reason they sell replacement props. Look into it and find a new prop setup to perform better for what you want. i.e. a 4 blade with more angle. Probably more fun to tinker with it that way.

"Boat propeller variations—primarily diameter, pitch, blade count, and material—directly determine a boat's acceleration, top speed, and fuel efficiency. A higher pitch increases top-end speed but reduces acceleration, while a larger diameter and more blades improve grip, acceleration, and handling at lower speeds, suited for heavy loads."