Weight and prop pitch

[sar3195]

I have a J 14' Carolina Skiff with a 15hp Yamaha tiller. The prop is a 9 1/4 X 9.
With just myself it runs fine at about 21mph. With another heavier person it lugs and the bow will not come down. It will not plane. It only gets 12 1/2mph.

Would a lower pitch prop help get the speed up or what will be my bet all around fix if there is one.

 

[Silvertip]

Re: Weight and prop pitch

With one person aboard, relocating some weight to the front would help. As would smart tabs which would provide some stern lift for what amounts to a very stern-heavy boat with just one aboard. A prop with less pitch would certainly help with hole shot it will raise wide open throttle rpm to the point where you might over rev the engine. Without a tach you have no clue what the engine rpm is now. Add a Tiny Tach so you know what you are dealing with.

 

[stevens]

Re: Weight and prop pitch

Ask the other person to sit forward while the boat gets over the hump, then move back as you throttle her up.

A lower pitch may also help, but may hurt your top end speed, and may also be too little when you're by yourself.

Smart Tabs may help. A bigger engine may help. A bigger boat may help...

 

[sar3195]

Re: Weight and prop pitch

Thanks for the information.

I think a larger motor would be the best thing. A much larger boat would not be too good because I have to keep it in our garage where we live. A good idea though...........

The Smart Tabs are another option I could try and they are not too expensive.

 

[Texasmark]

Re: Weight and prop pitch

You need to reduce your "on plane" speed to get the desired results with that engine. 21mph isn't that far over planing I'd bet. If you cut your prop pitch, you will go even slower putting you closer to falling back.

We used to do what Stevens said when we had a 10 hp and rented boats. I remember once, when I was a kid, I was out with the neighbor and his 2 sons. We planed out a 14' alum boat with all 4 of us in it with a 7 1/2 hp Elgin (not one of your heavyweight brands) by shifting the weight forward.....course we were so under powered, we had to stay there or fall back in the hole.

Trim tabs reduce your on-plane speed like Silver said. Like I read where one guy reduced his normal 18-20 mph plane speed to 8-10. That would give you some room to spare with the extra weight. Then if that doesn't fix the 2 person problem you might drop your pitch.

Course the idea of the larger engine would work best.

My 2c,

Mark