Newb needs some advice

[jaxbchangler]

Hey everyone i just bought this jon boat for $500 its a 14.4 sea nymph powered by a 2003 yamaha 9.9 high thrust 4 stroke. My question is what size prop should i use for more top end because right now i feel like the prop i have is too small (its a 8 pitch). The boat is pretty heavy the guy put all wood floors and the casting deck has a stainless steel frame. When im out on the water and give it full throttle its starts moving pretty good then it just starts feeling like too much throttle/power for the prop if that makes since? The motor runs great no problem what so ever with the motor. Any advice would be greatly appreciated!

 

[crabby captain john]

Re: Newb needs some advice

Did you have a gun when you bought that? Even if you trashed the rest (and the boat looks good) you are $$$ ahead on the motor alone. 1st thing to check is to see if you have a spun hub.

 

[NYBo]

Re: Newb needs some advice

Welcome to iboats!:welcome:

I think "high thrust" means the motor is propped to be a kicker for a large power- or sailboat: high power to get the boat moving but low top speed. You could probably do better with a different prop, as you suspected. Post over in the Prop Questions and Topics section for more specific advice.

Crabby is right: You got a steal of a deal!

 

[captain_ron]

Re: Newb needs some advice

Wow what a deal ! Enjoy it man !

 

[Jonnybbad]

Re: Newb needs some advice

Wow, looks like a clear win to me here. Good job! I'm gonna agree with NYBo's thoughts.

 

[jaxbchangler]

Re: Newb needs some advice

thanks yall! it was a friend of a friend who is getting divorced and needed $500 for a lawyer and ask me if i wanted to buy it . i said one word SOLD!!!!!! it even came with a working trolling motor, hummingbird fish finder and 3 batteries! its also 6 feet wide with a working livewell in the middle bench! i feel like i stole this thing :joyous: ........ sorry im new to the forum ill be sure to post this thread in the prop section

 

[Silvertip]

Re: Newb needs some advice

When it comes to changing props on a boat (or determining if what you have is correct) you need a tachometer. You make several wide open throttle runs with what you consider an average load while monitoring engine rpm. If the engine cannot reach the top end of the manufacturers rpm band you need to reduce the pitch. If the engine tends to over-rev (go higher than the top of manufacturers rpm band) then you need a prop with more pitch. So unless you do that, you are only guessing. The correct prop will provide only the speed that prop can provide, on that boat, at the recommended rpm. Yes -- you don 't have a tach. You can buy a "Tiny Tach" and permanently install it or use it only for testing.

 

[jaxbchangler]

Re: Newb needs some advice

When it comes to changing props on a boat (or determining if what you have is correct) you need a tachometer. You make several wide open throttle runs with what you consider an average load while monitoring engine rpm. If the engine cannot reach the top end of the manufacturers rpm band you need to reduce the pitch. If the engine tends to over-rev (go higher than the top of manufacturers rpm band) then you need a prop with more pitch. So unless you do that, you are only guessing. The correct prop will provide only the speed that prop can provide, on that boat, at the recommended rpm. Yes -- you don 't have a tach. You can buy a "Tiny Tach" and permanently install it or use it only for testing.

thanks for the advice im gonna go get one today and go try it out! ive only been on this forum for 1 day and already learned a bunch!

 

[agallant80]

Re: Newb needs some advice

Yeah I would pay $500 for just the motor on that thing. Prob more.

 

[Jonnybbad]

Re: Newb needs some advice

Yeah I would pay $500 for just the motor on that thing. Prob more.

Yeah, those motors are a high buck item from what I've seen. I'm pretty sure that they are meant to be used on bigger boats as a kicker like NYBo said. I don't know if this would be better, but maybe consider looking into the value of that motor, sell it, and get something different? You could potentially pocket some cash in the deal and walk away with an even more killer deal and a better motor for you application? Or maybe I don't have a clue. In the spirit of full disclosure, my database of knowledge on outboards is real small.

 

[crabby captain john]

Re: Newb needs some advice

You have a great one-- use it within its range instead of buying potential problems?

Yeah, those motors are a high buck item from what I've seen. I'm pretty sure that they are meant to be used on bigger boats as a kicker like NYBo said. I don't know if this would be better, but maybe consider looking into the value of that motor, sell it, and get something different? You could potentially pocket some cash in the deal and walk away with an even more killer deal and a better motor for you application? Or maybe I don't have a clue. In the spirit of full disclosure, my database of knowledge on outboards is real small.

 

[jaxbchangler]

Re: Newb needs some advice

i ended up getting a prop with 9'' pitch from this site and should receive it today ill let you know if it makes any difference.

 

[Jonnybbad]

Re: Newb needs some advice

You have a great one-- use it within its range instead of buying potential problems?

Fair enough. I stand corrected. *walk of shame*

 

[bonz_d]

Re: Newb needs some advice

I see that there is also a leftover side console for a steering helm. My gues it that boat is rated for a 40hp or something close to that. then add in all the extras like batteries, seats, trolling motor and my guess is that it's way under powered. Still would be a nice rig for small inland waters but don't expect a lot of performance from it even with a prop change.

 

[ThrottleBack]

Re: Newb needs some advice

thanks yall! it was a friend of a friend who is getting divorced and needed $500 for a lawyer and ask me if i wanted to buy it . i said one word SOLD!!!!!! it even came with a working trolling motor, hummingbird fish finder and 3 batteries! its also 6 feet wide with a working livewell in the middle bench! i feel like i stole this thing :joyous: ........ sorry im new to the forum ill be sure to post this thread in the prop section

lol I hate you. JP man, you fell into the steal I'm hunting. Welcome to the forum!

 

[jaxbchangler]

Re: Newb needs some advice

yeah so the 9 pitch prop only gained me about 1 mph haha but i did alot of research and these high thrust motors are geared really low to push big hulls at a low speed so i would have to find a really high pitch to make up for the low gear. Yamaha makes a 12 pitch for my motor but solas has an 11 pich for about half the price so i might just go with that to see if makes a difference!

 

[jaxbchangler]

Re: Newb needs some advice

oh and I figured why it sounds like its revving too high on WOT is because the pitch it too low for the way its geared for a planing hull. I never knew how much the pitch mattered until now:concern: