30 Yamaha tiller

[Skrimpit]

I have a 30 hp tiller Yamaha on a 15' tunnel Pathfinder.
I currently have a 3 blade black painted stainless prop on it with a ...13 F stamped on it???? The prop has been on the boat since I purchased it ans everyone says that the prop looks as though it has had some work to it and it looks like it needs to be changed out.
I have been told 4 blade and I have been told 3 blade so i don't lose any top end speed. Right now with 2 people and gear the boat does about 27 on the GPS. The boat takes off sluggishly on take off but once up it goes pretty good.
I am looking for some recommendations on different props and sizes that someone might suggest for me to buy.
Thanks for any help!!!!

Kevin

 

[whywhyzed]

Re: 30 Yamaha tiller

need a tach to prop it right, but 27 sounds impressive. I'd probably stick with that prop..the 13F
My 30 Yamaha had an 11.25P on it originally, I put a 12P cheapie michigan aluminum (it's slightly cupped) on my it on my 14' inflatable and it was much better. I used a tach and saw 5100 or so WOT with the 12P -it was 5500 with the 11.25P.
I find with my 30, that it's quite happy to rev to 5500, but the torque drops right off after 5000. It just gets noisier up to 5500

 

[Silvertip]

Re: 30 Yamaha tiller

Unless you know what the wide open throttle rpm is (actual -- not what the book says) we can't be of much help. For all you know, you have the best prop. The best prop is one that allows the engine to rev at the top of the recommended rpm band with an average load. The only way to know what the actual rpm is is to install a tach. Even a "Tiny Tach" would work for your purposes.

 

[Skrimpit]

Re: 30 Yamaha tiller

Thanks for the info on the Tach. I am going through some modifications with the boat and a tach will fit right into a switch panel I am adding. After I get it together and get some #'s I will make a post and see what you guys think.

Thanks again!

 

[whywhyzed]

Re: 30 Yamaha tiller

or you can just use an automotive multimeter with a tach pickup... or the tiny tach mentioned above.....don't need a tach permanently installed in a boat with a 30 tiller on it.