What prop do I need?

[ford4wd08]

I have a 85 yamaha 50 horse with a 11 1/4 X 14 - 6 aluminum prop on it. My boat is a 14 ft tri hull fiberglass bass boat. The model is a Fiberking Scout. I think the dry weight is about 550 lbs. I would say the operating weight is about 1100 to 1200 lbs. My boat top speed as of right now is 30 mph according to GPS at 4900 rpm at WOT. According to my manual the WOT is about 5500 rpm. I want a new prop because my old one has some wear and tear and I think I can get a little more performance out of my outboard. Any thoughts or suggestions or points in the right direction would be greatly appreciated.

 

[ford4wd08]

Re: What prop do I need?

Oh and here are some pictures that might help.... Thanks!

 

[steelespike]

Re: What prop do I need?

My research indicates that boats of similar size and weight run 13" and 14" props at 5200 to 5800. speeds 31-36 mph.
Your performance is reasonable but needs about 600 rpm.
I think before a prop you should refine your setup.
Motor in excellent tune?Throttle opening all the way? Antivent plate(just above the prop) about even with the bottom of the boat?
Bottom of boat clean and smooth.

 

[ford4wd08]

Re: What prop do I need?

Not exactly looking gains in all areas. I just think my prop is pretty rough and could use a replacement. I can check everything you mentioned. Just bought the boat a couple of months ago. Has fairly new plugs. I just think the prop looks rough and looks like it has pitting or something similar. I would like to get the RPM's right as well. I'm not sure how to adjust the motor and all. I have power tilt, but not trim. So after a certain amount of the throttle the motor wont move, and I have to tilt all the way down for the motor to get on plane. If I get it on plane with it much higher it will try to "skip" across the water and the only way to make it ride right is to trim/tilt it all the way down. Thoughts? How would I correct the level of the antivent plate?

 

[steelespike]

Re: What prop do I need?

Your prop probably does need replacement. But we need to be sure the setup is right.Iarethe tank and battery in the stern?
You might want to varify the tach.
As far as raising the motor.There may be a series of holes in the mounting bracket for vertical adjustment. Some motors
you have to simply raise it by hand hold the height with a stick layer on the top of the transom,until you tighten the clamps.
Some motors have holes in the mount so you can through bolt it to the transom.

 

[ford4wd08]

Re: What prop do I need?

Yes I have two batteries and a 12 gallon fuel tank in the stern. I do have a series of holes, but I'm not sure what would be there to put across to stop it. I can take some more pictures when I get off work. It is the factory tach, doesn't mean it is right necessarily, but I don't know another way to verify? My motor is bolted through the transom. I'm just afraid if I try to leave it at a higher level it will skip or whatever the correct term is across the water.......

 

[ford4wd08]

Re: What prop do I need?

FYI. Here are some pictures of the boat on the trailer. I hope I haven't relayed any information wrong as I am new to the boating world....

 

[ford4wd08]

Re: What prop do I need?

I went out and took some pictures of the outboard that might help. I tilted it all the way down as if I was in the water. Thanks for any replies

 

[ford4wd08]

Re: What prop do I need?

It does look like it might have been mounted a littler higher on the transom at one time..... I can see washer marks a set of holes down from where it is now.

 

[etracer68]

Re: What prop do I need?

It looks to me that your missing the trim pin (pin that goes in one of the five holes). I dont see anything that would go up aginst it either.

 

[ford4wd08]

Re: What prop do I need?

Well I guess I can look online and see what it supposed to come with from the factory. I have a cylmers manual and to my knowledge it doesn't say anything about a trim pin in it.

 

[etracer68]

Re: What prop do I need?

Heres a site, there calling it a tilt rod assemibly, also you will need the part that trusts aginst it. I dont know yamaha that well, but seems you are missing parts.
It looks like it didnt attach, the site is www.yamaha-motor.com

Look up your motor, and then go to bracket.

 

[boaterinsd]

Re: What prop do I need?

It does look like it might have been mounted a littler higher on the transom at one time..... I can see washer marks a set of holes down from where it is now.

Did you ask the previous owner about it? And why is the boat off the rear roller on the trailer? Is it to provide more tongue weight due to the smaller boat? JW

Welcome 2 iBoats......

 

[steelespike]

Re: What prop do I need?

Boy these guys are good I was so intent on checking the height adjustment indications i didn't notice these things.
The setup is perfect for playing with the height.
You boat does need to be on that end roller because now the support may be forward too much pushing up on the bottom
and could deform the bottom over time.
Do you trim up for the best speed and does the boat respond?
With all that weight in the stern It most struggle a little out off the hole?
Once you have checked the suggestions; A new 14" prop my help your performance A new prop may also
help the boat get out of the water better and may allow you to raise the motor a hole or 2.
You might check out the Turning Point Hustler prop.A very aggressive Aluminum prop that delivers stainless performance at aluminum prices.
If you have no ventilation(cavitation) issues now the motor may be too low.
I would wait for a new prop before raising the motor.
Sometimes you can gain speed raising the motor other times its just the satisfaction of knowing your not dragging too much motor through the water.

 

[ford4wd08]

Re: What prop do I need?

Boy these guys are good I was so intent on checking the height adjustment indications i didn't notice these things.
The setup is perfect for playing with the height.
You boat does need to be on that end roller because now the support may be forward too much pushing up on the bottom
and could deform the bottom over time.
Do you trim up for the best speed and does the boat respond?
With all that weight in the stern It most struggle a little out off the hole?
Once you have checked the suggestions; A new 14" prop my help your performance A new prop may also
help the boat get out of the water better and may allow you to raise the motor a hole or 2.
You might check out the Turning Point Hustler prop.A very aggressive Aluminum prop that delivers stainless performance at aluminum prices.
If you have no ventilation(cavitation) issues now the motor may be too low.
I would wait for a new prop before raising the motor.
Sometimes you can gain speed raising the motor other times its just the satisfaction of knowing your not dragging too much motor through the water.

I cannot trim up when I get the boat on plane. I just have tilt, not trim. The cylinder won't move after you go past a 1/4 of throttle. It does fine out of the hole with just me, but adding another person and it takes a second or two longer. Unfortunately in such a small boat that is the only places I have to store the gas and batteries.

The previous owner didn't change anything to my knowledge. He was not as mechanically inclined as I am and just ran it like it was. He was the second owner though. He didn't get to fish in it that much.

 

[ford4wd08]

Re: What prop do I need?

You when you move an outboard up or down with tilt and trim, and when it gets to the trim part it slows down and moves slower? Well mine is a constant speed up and down, and according to my manual my model only has the tilt option from the pictures it provides....

 

[ford4wd08]

Re: What prop do I need?

Did you ask the previous owner about it? And why is the boat off the rear roller on the trailer? Is it to provide more tongue weight due to the smaller boat? JW

Welcome 2 iBoats......

Oh and Thanks! I hope to learn a lot!

 

[ford4wd08]

Re: What prop do I need?

Ok, I went ahead and ordered the tilt rod assembly. It was like 40 bucks. Thought it would be a good idea to have it.

 

[ford4wd08]

Re: What prop do I need?

Boy these guys are good I was so intent on checking the height adjustment indications i didn't notice these things.
The setup is perfect for playing with the height.
You boat does need to be on that end roller because now the support may be forward too much pushing up on the bottom
and could deform the bottom over time.
Do you trim up for the best speed and does the boat respond?
With all that weight in the stern It most struggle a little out off the hole?
Once you have checked the suggestions; A new 14" prop my help your performance A new prop may also
help the boat get out of the water better and may allow you to raise the motor a hole or 2.
You might check out the Turning Point Hustler prop.A very aggressive Aluminum prop that delivers stainless performance at aluminum prices.
If you have no ventilation(cavitation) issues now the motor may be too low.
I would wait for a new prop before raising the motor.
Sometimes you can gain speed raising the motor other times its just the satisfaction of knowing your not dragging too much motor through the water.

Steelespike,

Is this the prop you are saying would be a good choice?

http://boatpropellers.iboats.com/Ya...H1-1013_Propeller/400/9988/?*******=597100392

I already like the price!

 

[ford4wd08]

Re: What prop do I need?

Heres a site, there calling it a tilt rod assemibly, also you will need the part that trusts aginst it. I dont know yamaha that well, but seems you are missing parts.
It looks like it didnt attach, the site is www.yamaha-motor.com

Look up your motor, and then go to bracket.

I ordered the trim pin, what part are you referring that the pin rest against?