Prop Size 02 60HP Yamaha 4 stroke

[Bunnerrabbit]

I have a 02 Carolina Skiff Semi V with a 60HP Yamaha and the only numbers I see on the prop is 13-G when I look up props for my motor they all come up with 12" pitch. Is my boat over propped or is that not a pitch number? when I am alone it runs great but when I get close to the boats weight limit of 1075LBS it does have problems getting on plane if people are sitting up on the bow and trying to get to the top speed. WOT with about 550LB load is 5950RPM but with a 1000LB load it will only get to 5000RPM. The last 1 1/2" of the throttle is just does not respond. Wondering how much speed I will loose dropping a pitch size? will it give me noticeable difference in power? Suggestions welcome. Let me add it is a stainless prop

 

[walleyehed]

Re: Prop Size 02 60HP Yamaha 4 stroke

With the correct prop, mr.rabbit, you may be able to maintain some lift and keep the speed up.
The resident Guru on that style of boat is Dhadley.......I'll see if I can turn him on to this thread....this boat can be tricky to prop and he spends a lot of time and money as a consultant finding out what works on these.
I'll see if I can find him...hang tight!

 

[Dhadley]

Re: Prop Size 02 60HP Yamaha 4 stroke

Let's take a look - It'd help to know what model Skiff you have but your scenario isn't unusual for a 4 stroke. One of the reasons the recommended rpm is at or past 6000 is so it'll not fall out of the power band with a load.

It's possible that 13G isn't the pitch, have you had the prop off to look for other numbers on either end of the hub?

Let's get the length of the boat and see if we can find any other numbers and go from there. Also, is the motor mounted all the way down on the transom? We're assuming, for the moment, there is no jackplate but have you tried raising the motor?

 

[Bunnerrabbit]

Re: Prop Size 02 60HP Yamaha 4 stroke

The boat is a 17ft Semi V 2002. As for the prop I did not see any numbers but went looking through the paperwork I got with the boat. Anyway it is a 11 1/2 - 13 pitch. The boat has only 1 small battery and no trolling motor. Just a small cooler with minimal gear. It does have a 22 gallon tank so thinking of that I guess my weight are off as I did not consider that. I might just try to run it 1/2 full from now on. The quoted WOT RPM's are with close to a full tank. Thanks for any more info.

 

[Dhadley]

Re: Prop Size 02 60HP Yamaha 4 stroke

OK, good info. Have you tried raising the motor a hole and seeing what that does? No jackplate, right? Mounted all the way down, right?

 

[Bunnerrabbit]

Re: Prop Size 02 60HP Yamaha 4 stroke

Thats for replying, I do not have a jack plate and the motor is mounted one hole up. Also if this helps, if you drew a imaginary like extending outwards from the bottom of the hull the tab you would mount a hydrofoil to is one inch below that line. That is when its trimmed level with the hull.

 

[walleyehed]

Re: Prop Size 02 60HP Yamaha 4 stroke

I'm on the side-lines watching here, but I'd bet Dhadley would like to see that engine up possibly 2 holes, but always test only 1 hole at a time.....that way we don't make too big of a jump and pass what may be the sweet spot.


Ok..I'll shut-up now...this is Dhadley's..

 

[Dhadley]

Re: Prop Size 02 60HP Yamaha 4 stroke

Nope, that's where I'd go Kenny. I'd start with the AV plate slightly above and then test. We'll end up going up from there depending on how good the prop is.