set up issues

[Damightybigfoot]

I have a picton159gts which is a 16ft padded v-hull, it has mounted on the rear a johnson v4 140 crossflow engine pre vro.

My issue is I have way too much bowlift when trying to get onto the plane, the front of the boat lifts up too much, we started by raising the engine up as was a tad low. See photos for difference, however we are still getting a lot of bowlift, to the point if we have a skier behind the boat it takes roughly 200yards to get onto the plane with a skier. Engine is propped to 13x19p which is recommended for this engine.

We removed a set of hydrofoils as they were causing chine walking a lot. Any idea what we could look at in order to try and rectify this bowlift problem?

 

[Texasmark]

Setup looks ok to me. Prop seems to be the right for a 140. Where do you attach your ski ropes? Where do you set your trim for the hole shot. What are you trying to pull out of the water?

I had a 17' Ranger BB with a Pad and a 115 Mercury. I Slalomed and weighed around 230 at the time. The prop was a Laser which was ported. I'd assume the ports on the laser would equate to your having more hp on a shorter boat. My son would pull me up, don't recall what he was doing at the helm, but I had no problem getting up in short order. Tow rope was on a bridle attached to the transom lifting eyes....one on either side of the engine...made for lifting the boat with a hoist when no ramp was available.....I don't see them on your boat.

If you are using a ski post, I can see you having your problem. The higher you mount the rope, the more the bow will be in the air....that's one reason you see Ski Natique and such professional ski boats running an inboard engine with thru hull drive....puts the weight in the center of the boat helping to get up on plane faster.....with the ski pole.

 

[ahicks]

To drag somebody 200 yards to get them on top is pretty poor performance. 200 feet would be nothing to brag about.....

For ski work, it would make no difference here what was "recommended". It would be all about propping the motor for maximum rated rpm. at wide open throttle.

If you have access to a 17" prop, I would try that for ski work, even if you have to manually limit your rpms at higher speeds.

If this boat is going to be around a while, you might consider going with a 4 blade. Alum. would be fine. You don't have to have stainless. 4 blade would help the bow lift issue, and provide the maximum amount of acceleration from a stop.

Hydrofoils suck. A real set of trim tabs might help. Downside, when working with a 16' boat, weight is really critical. Especially weight in the back of the boat. Which brings up the potential for anything back there now to be moved forward?

 

[southkogs]

You're seeing a lot of bowlift even without a skier? Is this new, or did you just get the boat?

Any chance she's got wet wood or foam inside?

 

[briangcc]

https://forums.iboats.com/forum/gen...s-not-engine-topics/10886444-control-problems

So I gather you haven't resolved your issue from the above post? And now added a skier into the mix?

I gotta echo the questions in the other post above...are you sure you are not overpowered for that length of craft? 140 seems like it very well may be.

In any event...have you tried trim tabs to get the bow down?

 

[Damightybigfoot]

Setup looks ok to me. Prop seems to be the right for a 140. Where do you attach your ski ropes? Where do you set your trim for the hole shot. What are you trying to pull out of the water?

I had a 17' Ranger BB with a Pad and a 115 Mercury. I Slalomed and weighed around 230 at the time. The prop was a Laser which was ported. I'd assume the ports on the laser would equate to your having more hp on a shorter boat. My son would pull me up, don't recall what he was doing at the helm, but I had no problem getting up in short order. Tow rope was on a bridle attached to the transom lifting eyes....one on either side of the engine...made for lifting the boat with a hoist when no ramp was available.....I don't see them on your boat.

If you are using a ski post, I can see you having your problem. The higher you mount the rope, the more the bow will be in the air....that's one reason you see Ski Natique and such professional ski boats running an inboard engine with thru hull drive....puts the weight in the center of the boat helping to get up on plane faster.....with the ski pole.

Since that photo we have raised the engine 2 holes as I could only get 42mph couldnt get anymore... it is off a pole however even without a skier it still has a lot of bowlift where you gotta stretch to see over the bow or look down the side of the boat.

It hasn't got those hooks only 2 single bolt tie down open end hooks at both edges of transom which you wouldn't want to pull a skier from as they'd break through the transom.

 

[Damightybigfoot]

To drag somebody 200 yards to get them on top is pretty poor performance. 200 feet would be nothing to brag about.....

For ski work, it would make no difference here what was "recommended". It would be all about propping the motor for maximum rated rpm. at wide open throttle.

If you have access to a 17" prop, I would try that for ski work, even if you have to manually limit your rpms at higher speeds.

If this boat is going to be around a while, you might consider going with a 4 blade. Alum. would be fine. You don't have to have stainless. 4 blade would help the bow lift issue, and provide the maximum amount of acceleration from a stop.

Hydrofoils suck. A real set of trim tabs might help. Downside, when working with a 16' boat, weight is really critical. Especially weight in the back of the boat. Which brings up the potential for anything back there now to be moved forward?

That is kneeboarding off a slipway where its struggling to plane worse with a monoskier... i want a 4 blade its trying to find one though... its an 1981 johnson 13spline gear case 4 baldes are extremely rare to come by for them

The hull is filled with foam up the nose designed that if it sinks the foam keeps it afloat... so nothing can be put up front tanks are rear mounted

 

[Damightybigfoot]

You're seeing a lot of bowlift even without a skier? Is this new, or did you just get the boat?

Any chance she's got wet wood or foam inside?

Brought the boat back in November because of quarentine not had chance to use it much... woods solid and foams dry no issues there, the hull and engine are both good just not set right somewhere

yes a lot of bowlift without skier

 

[Damightybigfoot]

https://forums.iboats.com/forum/gen...s-not-engine-topics/10886444-control-problems

So I gather you haven't resolved your issue from the above post? And now added a skier into the mix?

I gotta echo the questions in the other post above...are you sure you are not overpowered for that length of craft? 140 seems like it very well may be.

In any event...have you tried trim tabs to get the bow down?

not going to lie I forgot about that post....
even so that post was with a skier aswell...

I don't have access to a cheap set of trim tabs to try

 

[Damightybigfoot]

Setup looks ok to me. Prop seems to be the right for a 140. Where do you attach your ski ropes? Where do you set your trim for the hole shot. What are you trying to pull out of the water?

I had a 17' Ranger BB with a Pad and a 115 Mercury. I Slalomed and weighed around 230 at the time. The prop was a Laser which was ported. I'd assume the ports on the laser would equate to your having more hp on a shorter boat. My son would pull me up, don't recall what he was doing at the helm, but I had no problem getting up in short order. Tow rope was on a bridle attached to the transom lifting eyes....one on either side of the engine...made for lifting the boat with a hoist when no ramp was available.....I don't see them on your boat.

If you are using a ski post, I can see you having your problem. The higher you mount the rope, the more the bow will be in the air....that's one reason you see Ski Natique and such professional ski boats running an inboard engine with thru hull drive....puts the weight in the center of the boat helping to get up on plane faster.....with the ski pole.

This is where we raised the engine too now, it has helped decrease bowlift however it still occurs

 

[JimS123]

You didn't answer the question re. overpowering. A 140 is a lot for that little hull. What do the specs say?

If it were my boat the AV plate would be optimized and a Doelfin installed. Since you didn't like that idea, maybe it wasn't optimized or you had the wrong fin. Orrrrr, maybe your hull shape would be more suited to electric trim tabs.

PS - I looked it up for you. Couldn't find specs, but I found used ones with 75 and 90 HP motors. Does that tell you something???

 

[Damightybigfoot]

You didn't answer the question re. overpowering. A 140 is a lot for that little hull. What do the specs say?

If it were my boat the AV plate would be optimized and a Doelfin installed. Since you didn't like that idea, maybe it wasn't optimized or you had the wrong fin. Orrrrr, maybe your hull shape would be more suited to electric trim tabs.

PS - I looked it up for you. Couldn't find specs, but I found used ones with 75 and 90 HP motors. Does that tell you something???

Picton boats was only a small company was around for about 20 years then shut down, there isn't any specs on the boats anymore so nothing to tell you if its too big or not... however from factory the top model had mariner 130hp on them, none of them came with johnson or evinrude only mariners. So I wouldn't image 10hp would massively cause problems. Especially failing to plane, too big of an engine would cause it too try and flip itself over backwards when trying to plane rather than not get onto the plane surely? This is far from flipping backwards

What do you mean by the vent plate being optimized? Only work thats ever been done in my care is raised the leg up (see picture above) and removed the hydrofoils which caused chine walking

 

[ahicks]

It's NOT just about the horsepower of the bigger engines, it's about how much they weigh. There can be quite an increase to gain 10 hp, and many times the downside to that extra weight makes the move questionable. As mentioned, 16' boats are critical when it comes to weight. It's not just a question of whether or not the structure can hold the power safely. As you are finding, it's about how that hull handles the weight..... the changes in the way the boat handles.

As far as "optimizing" the engine height, mess with that all you like. As long as it's not venting, you aren't hurting a thing.

 

[Texasmark]

Picture is worth a thousand words: How about some RPM info at WOT and GPS monitoring of your 42 MPH. What I see is a deep V hull that rides "in the water" not on it, meaning the bow rides high, unlike a semi V that runs pretty much parallel to the surface...with it's flat transom area, comes up somewhat in the hole shot then levels off. If you really were at 42, you should have been on the "pad" by then, boat up "on the water", not in it, very little hull spray, leading edge exiting at the transom corners type thing, flat wake, hull should have leveled out significantly. With the AV plate up out of the water trim change effects would be thrust only and not as pronounced as when the engine is mounted at 20", AV plate is in the slip stream and acts like a variable trim tab.


Go to a Ranger Boats site and pull up some pictures of pad boats running wide open. Look at the pictures of the hulls and the picture of yours. Do the pictures look like the attitude of your boat?

Other thing I find confusing is that you seem to be running a standard alum prop which normally don't come with cupping, and with that engine height, I don't see why you aren't blowing out (prop ventilating) big time.

When running, do you have the trim at the position in your picture?

 

[JimS123]

Picton boats was only a small company was around for about 20 years then shut down, there isn't any specs on the boats anymore so nothing to tell you if its too big or not... however from factory the top model had mariner 130hp on them, none of them came with johnson or evinrude only mariners. So I wouldn't image 10hp would massively cause problems. Especially failing to plane, too big of an engine would cause it too try and flip itself over backwards when trying to plane rather than not get onto the plane surely? This is far from flipping backwards

What do you mean by the vent plate being optimized? Only work thats ever been done in my care is raised the leg up (see picture above) and removed the hydrofoils which caused chine walking

Your boat should have a capacity plate on it that documents the HP. Or, measure the boat and then go to the USCG site and do the calculations yourself.

Optimizing engine height means running as high as you can without ventilation. Its trial and error, requires numerous changes, while documenting the performance curve at each change. Every boat is different.

 

[Damightybigfoot]

It's NOT just about the horsepower of the bigger engines, it's about how much they weigh. There can be quite an increase to gain 10 hp, and many times the downside to that extra weight makes the move questionable. As mentioned, 16' boats are critical when it comes to weight. It's not just a question of whether or not the structure can hold the power safely. As you are finding, it's about how that hull handles the weight..... the changes in the way the boat handles.

As far as "optimizing" the engine height, mess with that all you like. As long as it's not venting, you aren't hurting a thing.

This is lighter than the mariner 130 as has no vro where the 130s have the oil system, weight 380lbs in total, it was set to the top hole about 1inch above bottom of transom, hit 42mph 5500rpm, wiuld go to 6000rpm but it was all cavitation, raised the engine up 2 holes and now it goes 44.2mph at5500rpm but won't go past 5500rpm

 

[Damightybigfoot]

Picture is worth a thousand words: How about some RPM info at WOT and GPS monitoring of your 42 MPH. What I see is a deep V hull that rides "in the water" not on it, meaning the bow rides high, unlike a semi V that runs pretty much parallel to the surface...with it's flat transom area, comes up somewhat in the hole shot then levels off. If you really were at 42, you should have been on the "pad" by then, boat up "on the water", not in it, very little hull spray, leading edge exiting at the transom corners type thing, flat wake, hull should have leveled out significantly. With the AV plate up out of the water trim change effects would be thrust only and not as pronounced as when the engine is mounted at 20", AV plate is in the slip stream and acts like a variable trim tab.


Go to a Ranger Boats site and pull up some pictures of pad boats running wide open. Look at the pictures of the hulls and the picture of yours. Do the pictures look like the attitude of your boat?

Other thing I find confusing is that you seem to be running a standard alum prop which normally don't come with cupping, and with that engine height, I don't see why you aren't blowing out (prop ventilating) big time.

When running, do you have the trim at the position in your picture?

42mph originally at 5500rpm, would go to 6000rpm however was cavitation for the last 500rpm, raised the engine 2 holes now it does 44.2mph all gps recorded 5500rpm but won't raise above 5500rpm. There isnt much hull spray once there however its not sitting kn the pad its going along with 3/4 the hull wetted.

Propellor is an omc 13x19p stainless steel propellor, its had work done to it with previous owner and cup added too it, it looks ali as omc painted their props black rather than polished. It was half painted when I brought boat so I been working on removing paint and polishing it all

 

[Damightybigfoot]

Your boat should have a capacity plate on it that documents the HP. Or, measure the boat and then go to the USCG site and do the calculations yourself.

Optimizing engine height means running as high as you can without ventilation. Its trial and error, requires numerous changes, while documenting the performance curve at each change. Every boat is different.

If it did have that plate is long gone! Or very well hidden!

 

[roscoe]

Picton boats was only a small company was around for about 20 years then shut down, ...from factory the top model had mariner 130hp on them....try and flip itself over backwards when trying to plane rather than not get onto the plane surely?

Well, Picton was around 40 years, then bought out.

Search and search all you want, but the only ones out there with a 130 or larger appear to be the newer 170 and 180 models. Can only find 159's with 90 or less hp. ? ?

And want to show us a video of a properly operated boat flipping over backwards, not a hydroplane and not an inflatable getting caught in the wind.

I'm adding my vote for you are carrying to much weight on the transom.

Have fun.

 

[Texasmark]

42mph originally at 5500rpm, would go to 6000rpm however was cavitation for the last 500rpm, raised the engine 2 holes now it does 44.2mph all gps recorded 5500rpm but won't raise above 5500rpm. There isnt much hull spray once there however its not sitting kn the pad its going along with 3/4 the hull wetted.

Propellor is an omc 13x19p stainless steel propellor, its had work done to it with previous owner and cup added too it, it looks ali as omc painted their props black rather than polished. It was half painted when I brought boat so I been working on removing paint and polishing it all

The black is probably Teflon if an OMC prop. Back in 1973 they got into the SS prop market with their SST prop: Stainless Steel Teflon (coated......apparently a cheaper grade of SS, not as much nickel content and more prone to corrosion than Merc. props). Included a brass ring that forced prop wash into the exhaust cone rather than diverged it as Merc. props had been doing for years....I guess the engineers figured something had to be different. Seems they abandoned the idea after some years and flared, and dumped the teflon and the ring....Ring was easily knocked off it you fished in the logs and stumps.

I guess I too will go the too much weight in the stern route. With that deep V hull you have nothing upon which to "set" the weight. Speculating that you aren't going fast enough for any "pad" area to do you any good. Nothing for the water to push against, or not enough water pressure to force the boat out of the water and force the bow down.