Do I need a different prop or do i need more weight in the front

[WTPhantom309]

Ive got a 78 Vip Fish/Ski 140hp 77 Evinrude, 2 truck batteries in bow in the center 19 pitch Alum prop 3 Bld 5200 Rpms but dont trust the tach but cant afford a new one(cause I keep goin Fishing) @WOT it porpoises If i dont trim all the way out i dont get enough RPMs usually it wouldnt bother me but its gets old when you run 20 or so miles up the rio grand I for got to add 18 gallons of fuel and on Battery in back. the hull is a trihull in the front and about 3 foot from the back theres a step type of thing and then it looks like the back of a bass boat could one of you guys help me not sure if this is a prop question or a "got to much led in my but" question

Derek

 

[LubeDude]

Re: Do I need a different prop or do i need more weight in the front

You deffinatly "DON`T" need more weight in the front, I would say just the opposite. A prop with some stern lift would help, but I think you are fighting a losing battle especially with a tri-hull. After getting on plane and at about the RPM you want to run, just bump the trim a little at a time untill is starts to bounce then back down a little. That`s your sweet spot.

 

[WTPhantom309]

Re: Do I need a different prop or do i need more weight in the front

I hate to sound dumb or somthing but do i need to move my trolling motor batteries to the back. and what kinda prop would you fellas recomend?
ss or alum would i go to a 17 pitch or ?? i really appreciate everyones help with this id just like to still run 45 or 50 and not bounce, if al all possible.


Derek

 

[WTPhantom309]

Re: Do I need a different prop or do i need more weight in the front

and yes Bass Fishin is a mental illness8)

 

[walleyehed]

Re: Do I need a different prop or do i need more weight in the front

"If" the tach is right, you're running right around 42mph...
If you "think" you're running 45-50mph, then the tach is about 600-800RPM off cause it would need to be running in the 5800-6000 range to get 46-48mph with an alum 19p prop. Do you have a friend with a hand-held GPS you could borrow? This or a new tach is the only way we could take an honest shot at what you need.

 

[LubeDude]

Re: Do I need a different prop or do i need more weight in the front

A prop with some stern lift would help, .

Sorry, I ment to say "BOW" lift.

How long is this boat?

 

[WTPhantom309]

Re: Do I need a different prop or do i need more weight in the front

the title says 17' but ive measured it every way i could figure but i always get 18'. i dont know if it makes a difference but the boat is rated for a 115 hp motor and i boght it with a 140 i was so excited about the deal i didnt check the max hp does this make a difference?

 

[WTPhantom309]

Re: Do I need a different prop or do i need more weight in the front

sorry kenny i didnt mean to not answer ur question, my GPS is at the bottom of lake IVIE dont ask long story but it involved a jet ski and my temper. (i wasnt on the jet ski.) I paced my dad and he left me at 45 by his GPS probly not enough info but till christmas thats all i got.

THIS JUST IN...

according to Mrs. WestTexasLineman that was the last trip of the season. might be able to bribe her to let me go again though:devil:

 

[LubeDude]

Re: Do I need a different prop or do i need more weight in the front

according to Mrs. WestTexasLineman that was the last trip of the season. might be able to bribe her to let me go again though:devil:

You can always say that you need to run the boat one more time to make sure the fuel stablizer is all through the engine.8)

 

[WTPhantom309]

Re: Do I need a different prop or do i need more weight in the front

she didnt buy it she told me to run it in the drum,
Ill think of somtin

 

[bassboy1]

Re: Do I need a different prop or do i need more weight in the front

Send her shopping and go boating while she is gone. But....
Be aware if she comes home early you might need to collect your clothes out of the yard, and sleep at a buddies house.

 

[WTPhantom309]

Re: Do I need a different prop or do i need more weight in the front

Buddies house? Ill just go back to the lake

 

[WTPhantom309]

Re: Do I need a different prop or do i need more weight in the front

Ill resurect this thread rather than start a new one,

The batteries in the front weighed 55 pounds apeice, moved one to the back figurede it would be better to have 55 pounds on the bow rather than 110# am thinkin about installing a stabilizer fin as ive got a friend in the bass club that had a boat like mine and said that it helped a bunch with porpoising. i dunno it might be worth a try. not gonna install it till i see if the weight transfer helped any.. anythoughts

 

[Silvertip]

Re: Do I need a different prop or do i need more weight in the front

Forget the hydrofoil. Smart Tabs are a much better alternative.

 

[Ghost Rider 2]

Re: Do I need a different prop or do i need more weight in the front

I can relate to Seamans problem I have a 18 ft Winner Wilcat. It has a 140 Mercury inline 6 cyl. It with not run flat on the water. I was advised to add a hydrofoil. The only thing it did was slow down the boat. Mine will run very fast but lacks power on the launch. Especially with a skier or tube behind. Mine has a 13X19 prop. I also can't seem to get full rpm very quick. I am not sure if a trim trab is what is needed for me or not. When my boat is up it is barely in the water. But it will porpuss. Have tried to trim it down, but it is far from level and sends water over the transom. Any help would be nice.

 

[Nova II 260]

Re: Do I need a different prop or do i need more weight in the front

WTL & GhostRider,
1st consider that the boat's attitude was fine when it came outta the box. Also, 110# is the weight of a bikiniclad young lady..and a BR boat should handle that just fine up front. At the age of your boat I would look elsewhere. Here is what a P.O. did to a boat I had. He apparently had the same problem you have. Porposing, slow and no or hard to plane. He added trim tabs, whale tail and 200# sand bags in the anchorlocker. It didn't help. Sold it to some unsuspecting fool...ME.
Well, the real problem was, the boat was carrying an extra 1200# of water and wet foam under the floor .... Weight your boat.

 

[WTPhantom309]

Re: Do I need a different prop or do i need more weight in the front

hole shot and planing time are better than my dads basscat with 10 more horses. I can pick the bow up (figured that out when i changed the bunkboards) and that was with the batteries in the front. i dunno i might just have to change props and run a bit slower. I think TexasMark referred to it as puttung the porpoise further out. If i cant get it to stop ill just deal with it till i can buy me a skeeter thanks for all the help guys ill try to find the foam and see if its wet. will let y'all know how it goes at the end of this month.


Derek

 

[Ghost Rider 2]

Re: Do I need a different prop or do i need more weight in the front

I don't think my problem is water wieght. My boat has been stored inside 365 days a year for the past 5 years. My problem came when my Chrysler motor blew up. Changed to Mercury and it has not been good since. I believe it is because the 6 cyl Merc is a lot heavier than the Chrysler. The Merc is faster overall, by 6 or 8 mph. But slow coming up to plane and ptopuss after it is up. Unless you are running almost wide open throttle. Very hard to run at a nice cruise. Also Chrysler had a 13X17 prop. Merc has 13X19. I installed Hydrofoil. It may have helped a little, but not much. It did slow boat down about 2 mph. I would like to try a prop change to see the difference. Any other suggestions? I am going to either fix it or buy wife a new boat.

 

[Nova II 260]

Re: Do I need a different prop or do i need more weight in the front

Buy her a new, bigger boat. She's told us she's tired of hearing you moan about this one...