needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

[suzuki1644]

I currently am running a 25 suzuki on a 16' 44'' with a 15 pitch prop... max rpm's at wot is 5500 and running 36 mph...can i go up to a 16 or 17 without losing to many rpm's...don't wanna spend $300 bucks on new prop and lose 1000 rpm's...now I'm running 36 mph with a 80lbs trolling motor..onboard battery charger...2 battery's..and 6 gallon gas tank..would like to get closer to 40 without straining my suzuki....what are my best options


thanks, kaleb

 

[Robbabob]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

Welcome to iBoats!

Let us know the max rating rpm for the motor and we'll help see if you can get to 40 from here. ;-)

 

[steelespike]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

36 is a very good speed.Is it by gps? What year motor?2 stroke or 4?

 

[wifisher]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

15" sounds like a lot of pitch for a 25hp. What is the reason for wanting to go faster? 36mph is a very respectable speed. Did you ever think about what happens to you/your boat if you hit a wave or wake at that speed?

 

[suzuki1644]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

Welcome to iBoats!
.
I found a chart on the net that said Max rpm's at wot for my particular outboard is from 4500-5500.... I'm running 5450 to 5500

 

[steelespike]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

$300 for a prop?? Is it gold plated?I would think even a ss prop for that would be under $300
Your at the rated rpm Increasing pitch may add a little speed but you would be lugging the motor.
This could cause premature repair problems and poor overall performance.
36 is close to amazing with the load you describe.Is it by gps are you sure its mph and not killometers?If its a fish finder or speedo they aren't particularly accurate.Again what year motor and 2 or 4 stroke?There are some things you can do to improve speed without changing props.

 

[Robbabob]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

Welcome to iBoats!
.
I found a chart on the net that said Max rpm's at wot for my particular outboard is from 4500-5500.... I'm running 5450 to 5500

You are right where you need to be with RPM... assuming the trim is correct. Be safe, be happy... you have what you have. Want to go faster???? get a bigger boat

Good luck!

 

[pootnic]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

Do they make 16 pitch prop for a suzuki 25hp?
Not even sure if it would turn without hitting,anyways...
Alot of people say you loose around 200rpm for each increase in prop pitch,I think your flying pretty good already,happy boating.

 

[suzuki1644]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

$300 for a prop?? Is it gold plated?I would think even a ss prop for that would be under $300
Your at the rated rpm Increasing pitch may add a little speed but you would be lugging the motor.
This could cause premature repair problems and poor overall performance.
36 is close to amazing with the load you describe.Is it by gps are you sure its mph and not killometers?If its a fish finder or speedo they aren't particularly accurate.Again what year motor and 2 or 4 stroke?There are some things you can do to improve speed without changing props.

I just recently looked at some props on the net and a powertech 16 pitch semi cleaver SS is just over 300$ with tax and shipping...yes I tryed 2 different GPS's and toped 36 MPH..not killometers...the Suzuki is a 97 year model 2 stroke 3 cylinder

 

[suzuki1644]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

Yes they do make a 16 pitch for a 25hp Suzuki...the only 1 that I can find is made by powertech...the diameter is 10.375...

 

[steelespike]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

Is the present prop a 15" ss. and what diameter? Does it have a strong hole shot?does it handle a load well?Do you have any ventilation (cavitation) problems at all?

 

[suzuki1644]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

Is the present prop a 15" ss. and what diameter? Does it have a strong hole shot?does it handle a load well?Do you have any ventilation (cavitation) problems at all?

yes the prop i'm running now is a powertech 15 pitch ss with about medium cup..diameter i think is 10.25...hole shot is ok..not blasting out but ok...with a load...me and 2 other people...we are all about 200lbs...i GPS us running 33... cavitation non at all

 

[steelespike]

Re: needing input on 25hp suzuki running 15 pitch prop vs. 16 or 17!!!

With that prop or a 16 you likely could raise the motor more.
In extreme cases you could gain a couple of mph.Your allready getting lots of speed but may gain a little.I would raise it to a point just before venting bercomes a problem.Pretty sure the 16 will kick a little hole in your hole shot and while it may inprove speed a little it will knock a hole in the rpm and topend with a load.