Trolling speed difference 13P to 17P

[habnut]

I am thinking about a variable pitch prop. My Etec idles at 6oo rpm . With a 17P prop, its a little fast for my liking for trolling. With a13P-17P variable prop, what would the difference in forward speed be, at 600 rpm? Sorry if the answer is obvious, but I just cant find it...Thanks in advance...Karl

 

[TXREBEL]

Re: Trolling speed difference 13P to 17P

how fast is it pushing you? I have a 20p prop and i still have to give it more throttle to hit 4-7knts

 

[steelespike]

Re: Trolling speed difference 13P to 17P

delete

 

[steelespike]

Re: Trolling speed difference 13P to 17P

Would help to know what hp and what boat
Usually a prop is not the solution to too fast trolling speed.You need to add a trolling plate or a drift sock.
Are you referring to a torque shift prop or a manually shifted prop?Neither is practical and won't do the job.
It appears a 13" prop will produce about 2. mph.depending on the boat and motor.A 17" about 2.6.
I don't know if the etec can automatically compensate for the 13" pitch the It appears the idle would be faster with a 13" prop.

 

[habnut]

Re: Trolling speed difference 13P to 17P

Thank you Steelespike...Its a 18.25 Sylvan rivetted aluminum with a 115 H.O. Etec. I was thinking of a torque shift prop.( Actually, I have never heard of a manual shift prop) I wondered about the motor idleing faster with the less resistance, and will do some checking into that. Probably, considering the cost of variable shift props, my best bet will be to ante up a little cash and put on a separate 4 stroke trolling motor. Thanks again ...Karl

 

[steelespike]

Re: Trolling speed difference 13P to 17P

Years back there used to be a prop you could dial through various pitches.
I believe there is a composite prop that can be changed to 2 different pitches.
In my research I used the sister Etec 90 hp test reports.A kicker seems like the expensive way out,also needless complication,weight,
steering,shifting,starting,fueling when a trolling plate is probably a 10 second operation.
I also was thinking a Torque shift is a very expensive proposition.

 

[habnut]

Re: Trolling speed difference 13P to 17P

Fair enough. I have a torq shift prop from an old mercruiser that is scrapped. Maybe I can do some horse trading, but I think I will take your word for it that the torq shift would not be satisfactory anyways.I have heard mixed reviews on trolling plates, but really have not looked into one very closely. Perhaps that will be my next mission haha...Karl

 

[82rude]

Re: Trolling speed difference 13P to 17P

yah steelespike, there was a prop years back that you could manually adjust .I have one ,it is off of a 1956 30hp Johnson .I would have to go find it and look at it but it varied something like 9p to 17 or so ,though don't hold me to that.

 

[Rancherlee]

Re: Trolling speed difference 13P to 17P

Another thing to watch for is many 13 pitch props will have "big ears" and bite the water better and actually make it harder to adjust trolling speed. I have a "big ear" 13 on my pontoon and with a 700rpm Idle I see 2.2mph but its very hard to adjust the speed from there as a SLIGHT bump to 800rpm pushes me past 3mph. I lucked out and picked up a Yamaha 9.9 HT off craigslist for 800$ with the skeg broke off and now have just about unlimited speed settings between 1mph and 6.5mph along with the ability to power MYSELF back to the dock if the main motor quits for some reason. When your 20+ miles down a chain of lakes its nice to get back to your own dock/trailer instead of just making it to shore.

 

[habnut]

Re: Trolling speed difference 13P to 17P

Oops...I dug out my old vari-pitch quicksilver prop.Turns out it is actually a 15P to 21P. Thanks for your replies, what a great website. ( sorry for sending ya on a wild goose chase Steele) I got lots of solid tips, now need to follow up on them haha...Karl