Am I missing something here ?

[Soonertoon]

Ok, Folks here's the deal. 22 ft Suncatcher , 2 log, 115 Yamaha. 12 p X 13.5 SS cupped Powertech prop. Nice boat, comfy, really like it . However, couple things I need help with. Hole shot to top end is very quick , 30 m.p.h. WOT. However , when cruising , 3000 rpm delivers 13 mph, 4000 delivers 18 mph , 5000 delivers 21 mph and top end is 25-26 . That's 2adults , 2 teenagers and full tank. I can't get any real speed advance over those rpm ranges and top end drops dramatically as well. Helluva lot more engine roar but not much increase in speed.
I'm convinced there is a helluva lot of prop slip in there. Funny though that from dead stop to wide open will pull another 5 mph top end. I run WOT very little if at all. Most time spent 12-15-17 mph. Am I all wet on this or am I on the right track with prop slip?

Second thing. At speed, ANY and I mean ANY trim AT ALL and the speed immediately drops noticeably. Motor was way too low in bottom hole so raised it one. Was puking way too much water all over the front of it above the level of the cover gasket and back into the center toon area. That made it better . Tried one more above and ventilated too much. At WOT unless I run it trimmed all the way down , she scrubs speed like a wounded duck. I've owned boats for 30 years and understand trim , etc. can't figure out this one though. You gotta get the. One cones up a little but on this bastard, the speed goes to shit immediately

Ok so there it is . Any constructive input would be welcome . Thanks everyone.

[HandymanHerb]

What prop do you have on it

[SamiGuy]

I am by no means a pro, but I have a 22' Sweetwater with same Yami. Turning a 13 1/2 x 17 and get Mid 30's top end. Two boats ago, (toon) , I had a spun hub that about drove me crazy until I figured it out. Just a thought....hope you can chase it down!!!
Sami
PS...Do you have strakes?

[slingshot]

No, you're right where you should be for your size boat assuming you have two logs without strakes. WOT of 30 is actually pretty good. A cruise of 17 to 19 is also average. Don't know if this is your first pontoon but know that a pontoon is more of a displacement type hull. Absent strakes, they are designed to go thru water, not on top of it so extra weight onboard will tend to effect top end speed more dramatically.

Sammiguy, I assume you have strakes or a third log. 35 mph is awesome for a 115 on a two logger 22'. My buddies 22 will get 32mph with his 115 but he has a third log.

[Soonertoon]

What prop do you have on it

Its in the first sentence of the post.

[Soonertoon]

I am by no means a pro, but I have a 22' Sweetwater with same Yami. Turning a 13 1/2 x 17 and get Mid 30's top end. Two boats ago, (toon) , I had a spun hub that about drove me crazy until I figured it out. Just a thought....hope you can chase it down!!!
Sami
PS...Do you have strakes?

I have the FB model 115 so not sure if there's a difference between the two other than electronics . Running this 17 pitch prop, are you pulling 58-6000 rpms at WOT? You know this whole prop thing is a big mystery in the end and it seems nobody really has a definite handle on it . Ive got a 12 p prop , cupped, running 6000 RPM at WOT and here you have the basic same set up running a 17 P. If you buy into the standard routine that for every degree of pitch you increase by, you will drop an average of 200 rpm. that being said, I would drop almost 1000 revs which isn't good for many reasons.
Now, if you tell me you are pulling the recommended RMP range at WOT with a 17 p prop, then that blows a wide open hole in what the prop folks are telling me as well as the conventional wisdom of selecting a prop based on the statement above
. Like I said, its all voodoo art. LOL . By the way, no strakes and U shaped logs.
Look forward what your feedback is .

[HandymanHerb]

What prop do you have on it

Its in the first sentence of the post.

Yep, I read it twice and still missed it, getting old

[Soonertoon]

What prop do you have on it

Its in the first sentence of the post.

Yep, I read it twice and still missed it, getting old

Ok, Folks here's the deal. 22 ft Suncatcher , 2 log, 115 Yamaha. 12 p X 13.5 SS cupped Powertech prop. Nice boat,

[slingshot]

My friend, you simply are not going to get any better performance than you are getting right now without going to a bigger motor or adding a pontoon and/or strakes. Below are the Yamaha performance bulletins for your boat. They show you are right where you are suppose to be. In fact, I you're hitting 30mph at WOT with a light load your doing real good.

http://yamahaoutboards.com/sites/defaul ... pp_pnt.pdf


http://yamahaoutboards.com/sites/defaul ... 24_PNT.pdf


Now get out there and enjoy that bad boy!!!!

[SamiGuy]

Sorry for the delay..learning how to run a dump truck.
OK.. Mind does have strakes, 2 logs. My WOT gives me 5600 RPM. Mine "was" a SS Ballistic 13 1/2 x 17 with cups. My prop guy took the cups out, but I think its still 17 pitch.
Very happy with my results. Hope you get this dialed in !!
Sami

[Crab Island Cruiser]

I have the same type setup. 07 Sunchaser, F115 Yamaha 4 stroke, 4 blade 13 x 15p. 28mph is my best GPS speed downhill with a tail wind. Lol.

My boat is twin tube no strakes.

[Soonertoon]

I have the same type setup. 07 Sunchaser, F115 Yamaha 4 stroke, 4 blade 13 x 15p. 28mph is my best GPS speed downhill with a tail wind. Lol.

My boat is twin tube no strakes.

your RPs still in the acceptable range at WOT with that prop?

[Crab Island Cruiser]

No. 5400 at wot. I usually cruise at 3500 or 4000. I'm looking into strakes and or a center log so I'm not planning on buying another prop til then.

[rancherlee]

It's the nature of a two logged beast. 30mph if your very lucky 26-28 is average for a 115hp on one. 12p prop sounds about right for those speeds also. You could go bigger diameter for more "traction" and try the 14x13 Yamaha Pontoon prop (turbo pontoon 1 stainless) I had goof luck with that prop when I had a Johnson 70 4 stroke, good hookup.

[Crab Island Cruiser]

I just looked at my prop, it's 13 3/8 x 15p. I was 3/8" short. Seems I've been coming up short all my life. Lol