question about my 6 horse johnson

[fanman]

I have a two blade prop on my old 6 horse johnson outboard motor, would a 3 blade prop make a difference on the speed of my boat?

 

[crazymanme2]

With a 6 hp motor you probably won't notice much of a difference but a 3 blade of the same pitch & design should have less slip which means more speed.Even with a 6 hp, get that motor so the cavitation plate is even or above the bottom of the boat.

 

[fanman]

I really just want to know if its possible for it to get out of the "hole" the boat is a 14ft semi v

 

[bassboy1]

With a 6 hp motor you probably won't notice much of a difference but a 3 blade of the same pitch & design should have less slip which means more speed.

While on a 6 hp, you aren't going to notice much of a difference, so don't waste the money, I do have to disagree with the above statement. It has been my understanding that all things identical otherwise (as in surface area of the prop blades, and general design), the two blade will be the most efficient. The reason Motorguide runs 3 blade props on their trolling motors is for weed issues, while the two bladers on the Minn Kota are supposed to be more efficient.

Also, the boat that holds the water speed record (powered by a modified 1989 Evinrude V8, back when Evinrude still made the V8), was set up to a point where only ONE blade of the 3 blade prop was in the water at a given time.

Granted, a higher blade count will give you better hole shot, at the harm of top speed. That is why many fish and ski boats tend to run 5 blades, as they are a heavy, cumbersome boat, and take forever to pull out of the hole, especially towing a skier. This probably isn't your answer, as they are doing it to pull out of the hole quicker. Not sure that your boat/motor combo is going to pull out of the hole at all.

 

[crazymanme2]

So if 2 blades are more efficient than why did the record holder have a 3 blade.I speak from experence,I used to race boats & 2 blades went out quite a few years back.They run 3 or 4 blades now & not because there slower. #-o

 

[wasilvers]

So if 2 blades are more efficient than why did the record holder have a 3 blade.I speak from experence,I used to race boats & 2 blades went out quite a few years back.They run 3 or 4 blades now & not because there slower. #-o

for your normal boat, 3 blades has more resistance than a 2 blade prop, but with more 'bite'. Running a 3 blade prop on a race boat, if the other blades are mostly out of the water to reduce drag, a three blade will provide more constant push than a 2 blade.

Maybe....

 

[crazymanme2]

Your on the right track =D>

 

[bassboy1]

Not saying your wrong (remember, I did say "it is my understanding"), but on the record holder, only one blade was in the water, acting as a single blade, but the three blades allowed that "one blade" to be in the water 3 times as long.

 

[Bugpac]

Not saying your wrong (remember, I did say "it is my understanding"), but on the record holder, only one blade was in the water, acting as a single blade, but the three blades allowed that "one blade" to be in the water 3 times as long.

Actually just 1/3 longer... I think..

 

[fanman]

O.K. now that I have started a great debate....

should I spend a 100$ on a new prop that has 3 blades vs my 2 blade prop on my 6 horse motor or is it not worth it?

 

[Bugpac]

O.K. now that I have started a great debate....

should I spend a 100$ on a new prop that has 3 blades vs my 2 blade prop on my 6 horse motor or is it not worth it?

Not worth it IMO..

 

[crazymanme2]

I agree with Bugpac.You do carry an extra prop with you though just in case?

 

[Tom @ Buzzard Bluff]

I really just want to know if its possible for it to get out of the "hole" the boat is a 14ft semi v

Think about it----will more blades on the prop translate to more horsepower or will your motor still be a 6 HP?

You don't need a different prop to 'get out of the hole'----you need more motor! Tom

 

[jasper60103]

I've heard some folks say they can get a 6hp to plane a 12' semi v tinnie,
but that also depends on setup and weight.
Those are neat little motors for fishing, but you will need to upgrade if you want more performance.

 

[fanman]

Thanks for all the advice