Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...help!

[DonEggerton]

I have a 1998 Sun Tracker Party Deck 21 that I restored 2 years ago. It had a 75 hp Force which last year I upgraded to a 115 4 cylinder Merc. - With this motor the boat would plane very nicely but not very fast. 25 - 30 MPH.

Just this past week I had a 150 HP Mariner EFI put on it. Now I can get it up to 40 MPH but when it comes out of the hole and come over it shoots water sideways about 6-8 feet from the bow. If I trim the motor too much it cavitates. The Motor is mounted as low as possible and I have a 21 pitch prop that is not very big in diameter. Before I go spend more money on props hopefully someone out there has had my problem and can make a helpful input.

thanks
Burleson, Texas

 

[rickdb1boat]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

Might consider putting some trim tabs on there. Also, you may need to raise the motor some and get a prop with more cupping. What type/brand prop are you running now? 21 pitch might be a bit much. Do you know your wide open throttle RPM's now?

 

[DonEggerton]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

I agree with the cupping....I actually just lowered it because it was one bolt holt high and the problem was worse. RPM was around 5000.....and then I till it almost out of the water and can get 5200-5300 and speed is 40 MPH. But the motor does not look correct because it is at a 20 angle from the boat.

 

[Jeep Man]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

Sounds like it is possibly NOT a long shaft model.

 

[5150abf]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

Trim doesn't have the same affect on a toon as a mono hull boat so you won't get alot by trimming the engine.

You changed the weight distribution on the boat so it runs differently, I would say you need to get some weight up front if possible either move a battery or put passengers up front, the only thing you changed on the boat was adding a heavier engine.

Also is that boat rated for a 150, sounds like alot of engine for a 20'.

 

[DonEggerton]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

It is a v-hull deck boat........more weight forward is not the answer I am trying to get the front end out of the water and increase the RPMs. But thanks for the help!

 

[ONERCBOATER]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

i have to ask, where is the anti-ventilation plate on the lower unit in relation to the bottom of the transom?
is there a possibilty of a pic to help us all become more familiar with the sitation.

 

[DonEggerton]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

I could take one tonight after work and Post it tomorrow.......

 

[DonEggerton]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

See Picture attached........Does the motor appear to be at the right heigth?

 

[ONERCBOATER]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

to my eye yes it does....
a few things come to mind looking at it, the prop appears to me to be approx right heigth. thinking you may wish to redistribute the load on your boat. What I am thinking may have happened is that you now have more power and that perhaps your prop is has more lift than the one you had before. 1st thing I would try would be to move loads such as passengers to the back of the boat....coolers as well anything you can move back that has some weight. To my eyes your drive is trimmed way too high and should be causing you to run with the bow up in the air.....that said you said that the bow was still too low.... so either your boat isn't ballanced correctly fore to aft....or you have a large hook in the hull....or the prop is creating too much lift. Myself I am betting solidly on fore to aft weight distribution. please tell us where your batteries, coolers, people and other heavy items are on board.

Others may chime in with far more exp than I and I would strongly recommend that you take their advice over mine.

Sean

 

[lmuss53]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

RPM's at low of acceptable range (5200 when on the verge of slipping, and 5000 at most when getting a good bite) + prop letting go of the water = too steep of a prop pitch. Borrow a 17 P and watch everything straighten out.

The motor height looks fine.

An aluminum deck boat rigged for fishing is the next boat on my list. Good luck with yours.

 

[lncoop]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

RPM's at low of acceptable range (5200 when on the verge of slipping, and 5000 at most when getting a good bite) + prop letting go of the water = too steep of a prop pitch. Borrow a 17 P and watch everything straighten out.

The motor height looks fine.

An aluminum deck boat rigged for fishing is the next boat on my list. Good luck with yours.

Most marine dealers will allow you to return a prop (provided it's still in new condition) if it doesn't work out. I bought one from the nice folks at iboats last summer. Their prop return policy clearly states they will not accept any props that have been in the water. I put it on, took the boat for a spin, and quickly decided it would not work. I removed it promptly and cleaned it up with the intention of trying to sell it, then later decided to ask if I could return it since it was still in new condition. I called iboats, told them everything, and the CSR told me to box it up and send it back and "we'll see what we can do." Two weeks later my card had been credited for the return. That's customer service, folks. The point of my rambling is don't be afraid to try out a prop, because as long as you don't hit something you likely won't be stuck with it. Just be sure and ask the shop in advance what their return policy is. Also, if you bought the motor from a dealer, I'd go there. You might get a little price break, special consideration, etc. Good luck Don. I know this kind of thing can drive a feller nuts.

 

[Cubbyblue22]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

Is that really the right height??? I still think it's a little high, maybe when you trim it down it would be a little better looking in my perspective but I could be wrong.

 

[ONERCBOATER]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

lol well i have to ask....
can we get a pic with the motor trimmed down to level with the hull.... as it would be on a well behaved boat.

Sean

 

[1nebel0]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

You are pitched too high for that boat...one can picture based off your post that trimmed down the cavitation plate looks to be about right..The higher you mount the motor the harder it will be out of the hole..You need to drop the motor as low as it will go. I am with the post above...17-19 pitch... I am running a 11 pitch on my 32ft Tracker with a 115h.p. you have to be in the 5500 range..............good luck

 

[Mr Crabbs]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

Don, doesn't the Party Deck have the batwing fiberglass hull (in crosssection)? I loved that boat, always wanted to get one but Tracker quit making them.

 

[Russell48]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

I run a 19 pitch an it's great with no prob with 5 adults on a 24ft toon

 

[captkevin]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

Wouldn't a 4 blade prop help out?

 

[Bamaman1]

Re: Upgraded Motor to 150 hp--- now 1998 Sun Tracker Party Deck 21 will not plane...h

A deckboat has different propeller needs from a pontoon boat.

I suggest you take the boat by any boat dealership in your area that's good at setting up motors/propellers. They should be able to give you suggestions to what you can do.

I am a fan of Bennett trim tabs on any hulled boat that has problems keeping the bow down--$500 item. You might need a jack plate to slightly lower the motor height. At the least, you might need another propeller of lower pitch.