Something seems off...

[cwd56]

Hello guys,
I have a 2015 Sun Tracker XP3 (tritoon) with a Mercury 150HP. We love the boat, but I know I am not getting my top speed where I should. WOT is only about 4500-4700RPM and 28mph with medium load. Even loaded I get 25mph with significantly more people on board. The prop is the Mercury SS prop that came on it, 15.3 x 14P RH.

Am I wrong in assuming I should be getting more out of it? Thank you for any help.

Chris

 

[WaterDR]

Your rpms are way too low. Should be more like 5500 to 6000 at WOT. Your prop has too much pitch.

Did it ever run correctly? Who put that prop on it?

 

[ahicks]

Yup, get the rpm's right, and you'll wake that boat right up with a very noticeable performance increase. Might not be a lot faster, but you should pick up noticeably more punch in about all situations.

 

[cwd56]

It's the prop that came on it from the dealership. I bought it new. It's always run that way.

 

[ahicks]

Maybe lesson learned? Dealer should have put the right prop on it for you. If it was delivered to you with the prop you have, to my way of thinking, you would have been within your rights to demand the correct prop be installed - at their expense!

 

[HotTommy]

cwd56,
If you do decide to change props, check out the forum here on iboats that deals exclulsively with prop issues.

 

[cwd56]

Maybe lesson learned? Dealer should have put the right prop on it for you. If it was delivered to you with the prop you have, to my way of thinking, you would have been within your rights to demand the correct prop be installed - at their expense!

I have contacted another Tracker dealership and they've verified it's the correct prop. They also the factory installs the engine, so height should be ok. I'm going to try something next outing before I start changing anything. The dealership agrees something isn't right, he said I should be pushing 40+mph.

 

[Silvertip]

Could be that the throttle isn't opening fully. Simple adjustment.

 

[cwd56]

Could be that the throttle isn't opening fully. Simple adjustment.

Definitely going to check this. The dealership I bought it from said a few odd things when I bought it and really lost my trust. One thing that really stood out was how pushy they were to get it in for the 20hr. Said Mercury uses a different oil for the break in and they needed to change it after 20 hrs. Mercury said it didn't need a 20hr service, first service was at 100hrs.

 

[WaterDR]

Well something is not right, that's for sure.

If you are really at WOT....you have the wrong prop. If the throttle is not fully engaged or some other issue, then you really are not at WOT.

You should be at 5500 to 6000 RPMs at WOT at load.

When the boat is running and you start to trim the motor up, will the RPMs increase?

It's also possible that your tach is jacked too and you are actually making more turns then you think, but speed is still too low.

 

[ahicks]

Maybe talk with a few mobile techs to find one that seems to know what he is talking about, and have somebody that knows what's going on check it out. Going to cost you something, but that should lead you down the shortest path to getting it to run the way it's supposed to. He'll likely know, pretty much by ear, if your tach is feeding you BS as well.

The Tracker factory rigged engines means nothing when it comes to supplying you with the correct prop. Mercury has absolutely no idea regarding what kind of boat that engine is going to be married to. For that reason, they're shipped with a standard prop, which in my experience is WAY too big. If somebody that knows what's going on at the dealership level (rare at Tracker Dealers) doesn't intervene, that's the prop that going to be installed when you get the boat....

 

[cwd56]

The prop seems to be the go to for my set up. Even on the Mercury site they have a test on a 24 XP3 with the 150hp and got 38mph@5800 rpm, same prop as mine. I just need to figure out why I'm not getting the rpm I need to get. I'm going to play with it some asap and see what I can figure out.

When I trim up, I get some ventilation and rpm increase, but when I have a good bite, I don't think I ever get over 5k on thebtach. I am going to pay a lot more attention next time out and two gps speeds to verify. I really hadn't put much into it until a friend with a similar set up said something.

 

[WaterDR]

My money is on the wrong prop.

If this were me, I would take the summer off. Go to a prop shop and borrow another....they will sometimes loan them. Slap it on and go. But to be frank, a 14P is really not a lot of pitch for that motor.

 

[WaterDR]

How long is the pontoon?

 

[cwd56]

How long is the pontoon?

It's a 24 foot tritoon.

 

[ahicks]

Missed the prop size in the original note. Doesn't sound that far off to me either. Is there a chance this engine has a break in mode built into the controller? That might be worth looking into as well.

 

[Silver Eagle]

My 07 StarCraft 24 ft got better top end and it had a 90 hp 2 stroke Mercury. I'd contact Mercury direct. Dealers lie,,especially if they sold it to you.

 

[cc350]

Try a 15x13P cupped prop.