porpoising checkmate

[billmart67]

I have a 87 enforcer w/225 efi , 10" jackplate 21 pitch apollo prop(i know not the right prop). the motor is set at centerline of prop shaft is 3" below very bottom of hull. If i trim past nuetral the boat starts to chine walk. My speed on the gps is only 55mph. The motor only 86 hrs.,Runs good and strong. Any input would be great.

 

[Vandalizer]

Sounds like your problem is the chine walking, not porpoising. You can try different motor heights to see if that helps, but you'll probably always have a little chine walking. You really just need to learn how to drive it-- it's been addressed in other threads, but it falls off the chine in the direction it rolls. i.e. when it rolls starboard, it falls off the starboard chine. So in that case you want to correct it with a quick steering bump to port and visa versa. You have to get it under control with steering input, don't try to throttle through it.

 

[mcnelson77]

How does the boat respond to a hole-shot? Does the prop cavitate at all or does it just get up and go?

 

[TheNerd]

You need to play with the set up, motor height and props. But the speed doesnt sound too far off. I would have thougth maybe 60 with a 225 on that boat. But I could be wrong.

 

[billmart67]

porpoising enforcer

my mistake i ment my 87 enforcer porpoises when i trim it past nuetral. sorry for the screw-up!

 

[billmart67]

hole shot is pretty good, a little slip . but that could be the wrong prop.

 

[boatman4021]

I have the same boat with the same motor and the same prop. The apollo is a good prop on the Enforcer. My boat has the same problem. I have found that if I trim slowly just a click at a time as the boat gains speed, it's not so much of a problem. Trim to much to fast, and you can't get it to top speed. 55 is a respectable speed for that boat. I have a 250 intake (4 hole instead of 2) and the tuner has been cut. I seen 61.2 last weekend at Lake Cumberland. boatman

 

[JBS]

boatman is right.I had a v8 on mine and it did the same thing.

 

[meantrump2]

could you

explain as to rather you use a hydrofoil or not. These are wonderful items to have. They plane out very guick,I have one with torque tabs built in and made a HUGE difference

 

[Rob B]

I responded over on S&F, but my only success so far is having the trim tabs even with the bottom of the boat. The only difference between your Enforcer and mine is the setback and horsepower. I think the 24' pulsares don't have the porpoising issues that I know of but are basically the same hull.

Edit: Tomorrow I'm trying bob's stabilizer with the tabs in the up position and will post the results.

 

[Rob B]

Here's a picture of Bob's Stabilizer plate mounted on the motor, it made a big difference getting out of the hole and stop the topend porpoising, also a picture of the trim tabs even with the bottom of the boat. See Checkmates on the lake thread and look at the Enforcer running with the plate and tabs in the up position.

 

[Double J]

Too me it looks like your trim tabs are on upside down. The ribs should be on the up side and the flat side should be down(the side that touches the water). I found that once you find the right motor height and prop(the key is one with alot of bow lift) you shouldn't need tabs at all. I only use tabs in seas never in the bays or the river.

 

[Rob B]

Too me it looks like your trim tabs are on upside down. The ribs should be on the up side and the flat side should be down(the side that touches the water). I found that once you find the right motor height and prop(the key is one with alot of bow lift) you shouldn't need tabs at all. I only use tabs in seas never in the bays or the river.

Those tabs are installed correctly, I have the bennett sport tabs. http://bennetttrimtabs.com/catalog.php?vID=78&catHome=1&imgCheck=2. I'm going have my 24P raker worked then try that without the stabilizer plate and the tabs up.

 

[Daddio]

I have tabs on mine and porpoising is not a problem .
I think you need a prop with more bow lift ... I dont know appollo props though ... When trying to run choppers mine had the same porpoising
and 4 blde bow lift props helped

My boat is a 23 Enforcer 225efi w/ 250 upgrades (boxes and intake)
I was running a 24p TrophyPlus at over 60 ..motor is about 6 inches deep

Daddio

(I said was running but it thru an ear so I am posting another thread for some prop help)

 

[Rob B]

Talked to my prop guy earlier, told him about the porpoising issue with the Enforcer. He confirmed what Double J said; motor height and a prop to carry the bow. So i'm going to have the 24P raker cupped then play with engine height. I'll post the results when the prop comes back.

 

[Double J]

I've tried a bunch of different props and that was my finding. I've even sent a prop off which carried the bow good, to have thinned balanced and blueprinted and come back and it wouldn't carry the bow. The boat would porpoise at top end. Sent the prop back and told him I needed more bow lift without losing rpm and what a difference it is. The boat is like a total different ride. I haven't measured my prop height but i'm running about a inch higher on the jack plate with no porpoising. so that is why I say when you get a prop with enough bow lift the porpoise should go away. Of course any boat will porpoise if you run too much trim @ not enough speed for the amount of trim being tried.

 

[Rob B]

Double J can you get a measurement of the center of propshaft to the bottom of vee. I just measured mine it's 3" below the vee.

 

[Double J]

Will do.

 

[gwcpa]

I realized last night that my boat porpoises too. Never really thought much about it because I can either trim up and power through it or trim down and it stops. Starting thinking about this thread as it was doing it.

If I trim down to stop it the speed drops a lot because I'm sticking the bow in the water.

Has a slow bounce around 50-55 when trimmed up moderately. I don't think it does it if there is a small chop on the river. It was flat last night.

If I speed/trim up and the boat "lifts" it goes away, or if I slow down around 40-45 and trim down it does not do it.

Had 2 people and somewhere around 45 gallons in the boat.

 

[Rob B]

I realized last night that my boat porpoises too. Never really thought much about it because I can either trim up and power through it or trim down and it stops. Starting thinking about this thread as it was doing it.

If I trim down to stop it the speed drops a lot because I'm sticking the bow in the water.

Has a slow bounce around 50-55 when trimmed up moderately. I don't think it does it if there is a small chop on the river. It was flat last night.

If I speed/trim up and the boat "lifts" it goes away, or if I slow down around 40-45 and trim down it does not do it.

Had 2 people and somewhere around 45 gallons in the boat.

What are you spinning, setback and propshaft height in relation to the vee?