Need Help River Rocket Owners, Please

[Fairbanksrabbit]

I'm kinda a problem with my 18 Ft Charger STV, (Needle Nose) it was fine when I had the 2.4 bridge on it, the odd time in the high 80's to low 90's it would lift, I would get out of the foot throttle slowly and it would settle back down, didn't want to get out of it too quickly and stuff it in. Now I have a 260 on it and it is way more frequent, Sometime at 75 and 80 under hard acceleration it will do it, ( running a 4 blade 26P cleaver on it) but now up top it happens super fast.... 95 to 97 ish. The last time I was out last year..... Last October... Lakes freeze here in November. I got out of it too quickly and when it landed back in the water, it landed flat the prop blew out and I did a 180 degree turn to the left in about a 300 foot radius at 85. Broke three ribs on that one...... lol. Was glad I went out with a spotter boat.

So it is time to do something about this. My boat is trapping too much air underneath. I think it is because the center pad is too short in comparison to the out side sponsons in length, and the pad should almost be an 1 1/2 to 1 3/4 deeper. I would like to get some measurements on a river rock bottom. Please. Any help you can give would be greatly appreciated.


Thanks Chris






343023

[patchesII]

Sounds like your setup needs some help. Are you over trimming it? What setback are you running and propshaft height?

Those are totally different bottoms. Some have added 1" to the pad of those early tunnel v's to help reduce lift

[Fairbanksrabbit]

"Sounds like your setup needs some help. Are you over trimming it? What setback are you running and propshaft height?

Those are totally different bottoms. Some have added 1" to the pad of those early tunnel v's to help reduce lift"

Yes, I have heard of that. But if I'm going to modify the bottom of the boat I want to try to get as close as I can to a bottom pad that works well and achieves good top end speed.
Set up is good, 15x26 4 blade Mercury Cleaver 8200 rpm, set back is 8 inches, prop shaft is 3/4 inch to even with the bottom depending on weight. These boats will not bust 100 mph and have a bad habit above 90 mph! that is what I'm trying to correct. It has too much wetting surface and the pad is only about 5/8 from the V. I want to lift it out more, and bleed some of the air out. And get the boat to fly more.

I am looking for measurements on an STV.... Preferably a River rocket. If you click on the pic in the 1st add... and print it. Then take the measurements I would greatly appreciate it.

Thanks

[cherokee_chief]

Ditch the 4 blade for a 3 blade 14.5 x32 cleaver.

[scott reierson]

Ditch the 4 blade for a 3 blade 14.5 x32 cleaver.

I have a 84 STV needle nose. was running 20" 260. and now a 15" 280/1:87 Sporty on CMC Hydro plate. Prop shaft level or 1" above the pad. To me after 50+ Boats this boat is a blast to drive. The bottom was way ahead of its time. The MOD VP and River Rockets filled in the blanks.

I run 24, 26 and 28 yamy 3 blade drags. Boats will run 110 with a 26 drag no problem at 8K+. Runs 90s with no drama. I have found these boats with high horsepower do no want much trim they run very flat. Mine accelerates very fast.

At about 80 I can really feel the deck pushing the boat down. If mine lifts to much i tap the down button. Motor likes to be mostly in a nuetral trim

My boat does not want a cleaver... tried a variety of them. Choppers are a bad idea.

I agree with the above comment. If you a trimming out alot, thats asking for trouble. Or your prop, etup and weight distribution is off. Unless your boat has been modified or repaired incorrectly I would not think there is anything wrong with the design. Its just the way they run. Flat and fast. Get a Yamy drag or drag clone and try it. Much less drama behind the wheel

Scott

[Fairbanksrabbit]

I agree with you, I just have seen pics that my friends have taken at high speeds and there is way too much boat in the water. 4 feet at least running flat and 2 1/2 feet at a high angle of trim 3 or 4 degrees. Any higher it's just too flightie and a torque tamer is a must on these boats other wise they crab 5 or 7 degrees. I just want too build a faster pad and get more boat out of the water.

Scott, is your pad totally flat? And how high or how far down is it off your V?

[Fairbanksrabbit]

Mine is only 3/4 of an inch343038