Top speed of 96 180 Tourn Pro with 115 ELPTO

[Auxlarry]

Hi everyone!!
My son just purchased a 96 180 Tournament Pro Starcraft with the Merc 115 ELPTO. the boat is in good shape and after a tune up, link and sync it runs good but it will only do about 30mph with two of us in it at 5250rpm. Is this about right for this boat?
Thanks!!

 

[SkiDad]

are you testing speed by GPS ? that RPM seems right but I think you should be closer to 40. is that 5250 full throttle or just where you are stopping ?

 

[Auxlarry]

Yes, it is GPS speed and at WOT. Can only get about 33 mph with a single person in it. Can't see any info on the prop but I haven't pulled it off to look in the back of the hub but it looks like a stock three blade.

 

[Watermann]

Find out what pitch the prop is and you can plug the numbers into a prop slip calculator and see what the % is. Sounds to me like the speed is about 10 MPH slow at least for that set up. What's the hole shot like? Does she just jump right up and set you back in the seat or is it a slow wallowing process to get on a plane, somewhere in between?

Would be nice to see a couple pics of your new to you Starcraft!

 

[Alumarine]

Try another prop.
Maybe weigh it as well.
What motor is it rated for? I'm guessing at least a 150.

 

[Auxlarry]

No Title

Watermann,
It doesn't jump like my 180 Wellcraft 115 v4 does but you can feel 3 and 4 kick in right after throttle up, It does seem a bit slow to plane off but doesn't wallow around. As I'm no that familiar with the Merc 2+2 it just doesn't feel like it has the quick response I would expect. I'll pull the prop tonight and check on it.

 

[Auxlarry]

Marc c,
I'll pull the prop tonight and check the numbers on it. Yes, the boat is rated for 150 max but the 115 is plenty adequate for what my son needs. We did weigh it at his work, boat with about 10 gals of fuel, no gear and the trailer were 2,319 lbs.Seems about right for this boat and trailer.

 

[Watermann]

Yeah the weight sounds spot on to me for the whole package. There's something going on if the motor is healthy and since the RPMs are too low I'm thinking you'll find at least a 2" pitch too much prop on it. Is the prop a 3 blade and is it SS or AL? Too much pitch will be lugging the motor out and lowering your top end as well as making the hole shot sluggish.

I suggest if you haven't already since in the testing phase to warm the motor on muffs and do a compression check on the cylinders just so you know and have peace of mind the motor is healthy.

 

[Auxlarry]

Watermann,
Comp is 134-138 on all four. Rebuilt the accelerator pump and pulled, cleaned rebuilt carbs. I'm going to check the timing again tonight and pull the prop which is a three blade.

 

[Auxlarry]

Well, work got in the way and I finally had a chance to get into this engine. The prop is a 13.75" x 15" pitch which seems to be fine now that I dug into the engine a bit more. When my son purchased the boat the seller told him it had been tuned up and the fuel pump had been rebuilt, After checking deeper and running a fuel pressure check I was only getting about 2psi out of the fuel pump. Pulled it apart and found that the check valves did not have the rubber disks in place, only the plastic stiffeners. Ordered the repair kit, rebuilt and rechecked, 5.5 psi!! Took the boat out and immediately felt the difference and ran the boat at 42 mph on the gps!! At my age I should know to check everything!! Thanks for the help and hope everyone has a safe and fun boating summer!!

 

[Alumarine]

Glad you got it sorted out!

 

[Auxlarry]

Well, shouldn't have talked nice about this motor...lol Son had it out and it's doing the same thing, sluggish acceleration and low rpm! Not sure where to go now as I have changed/rebuilt the entire fuel system and its getting good strong spark. I did notice though that it doesn't seem to be charging. Could the regulator be causing this issue?

Thanks,
Larry

 

[Watermann]

Larry you may want to ask a mod to move your thread to the Merc engine forum to get some fresh eyes on the issue. :mod: