Driving advice

[Wrekked]

Hey guys,

I've been out racking up the hours on my fourwinns H180 150 etec, I have found its happy spot with trim and speed (30mph @ 3000 rpm, trimmed up 1/4 on the guage), but I ran into some rough spots from general waves and wakeboard boats and had to slow down to 25mph to keep the family happy. I noticed the engine jump to 3500-4000 rpm during these slowndown times and I would lose plane. I tried messing with the trim but more down just rose the bow and made me fall off quicker and going up ventilated. Is there something I'm doing wrong or is it just that it's too slow? I have the enertia prop on there already not sure if its the 18P or 19P. Im considering putting on smart tabs if this is just due to being too slow. Don't really want to do a 4 blade as I love my 55mph top speed

 

[harringtondav]

It sounds like your "messing with the trim" was trimming further up. Correct? Generally the slower you plane, the lower you adjust your trim. To plane at my lowest speed I have to trim nearly full down.

Your "sweet spot" sounds good, but what is your wide open throttle (WOT) rpm at 55 mph? What is your motor's WOT rpm spec.?

 

[tpenfield]

With a load of people and running into haves, you are probably getting a bit of ventilation (air) at the prop. You will loose speed and fall of plane as the prop has lost its grip. Also with a load of people, the prop may have the tendency to cavitate, which is a vacuum on the back side of the propeller blades.

In either case the prop will loose grip until it can re-gain its 'bite'.

 

[Wrekked]

I believe I was somewhere around 5600rpm @ 55mph. I believe max is 6000 rpm. I was trimmed about halfway up. The water was very calm for this lake when I maxed it out (slight chop). The boat had no issues with 2 adults and 2 children in the boat and 2 children tubing at 25mph. But I did have 2 in the bow, me at the helm and the other adult in the back. In my scenario where I lost plane I had myself and my 2 year old at the helm and my 5 year old and wife in the back.

yes, I would try to bring the prop down. Maybe I didnt bring it down enough. Ill give it a try again today although the water seems calmer today. Was tricky with a sleeping toddler on my lap. So if I'm reading what your saying right, I really have 2 options, lose plane or go faster?

It also tends to porpoise around 35-40 mph which I am used to as normal. I assume theres nothing to be done about this without tabs as well? This doesnt bother us, just more curious. Its a weird spot that I can replicate time and time again. If I trim up just one or two slight presses it seems to reduce it by about half but anymore and I ventilate again.

 

[Horigan]

I usually trim down a bit to eliminate porpoising.

 

[JASinIL2006]

I believe I was somewhere around 5600rpm @ 55mph. I believe max is 6000 rpm. I was trimmed about halfway up. The water was very calm for this lake when I maxed it out (slight chop). The boat had no issues with 2 adults and 2 children in the boat and 2 children tubing at 25mph. But I did have 2 in the bow, me at the helm and the other adult in the back. In my scenario where I lost plane I had myself and my 2 year old at the helm and my 5 year old and wife in the back.

yes, I would try to bring the prop down. Maybe I didnt bring it down enough. Ill give it a try again today although the water seems calmer today. Was tricky with a sleeping toddler on my lap. So if I'm reading what your saying right, I really have 2 options, lose plane or go faster?

It also tends to porpoise around 35-40 mph which I am used to as normal. I assume theres nothing to be done about this without tabs as well? This doesnt bother us, just more curious. Its a weird spot that I can replicate time and time again. If I trim up just one or two slight presses it seems to reduce it by about half but anymore and I ventilate again.

Although you often can reduce porpoising by adjusting the trim, if it persists, you might look into something like SmartTabs. A lot of folks find they totally eliminate porpoising. I know they did exactly that for me.

 

[Wrekked]

Thanks for the advice guys, everything went super smooth today. Was able to cruise in some heavy chop at 25mph around 3200 rpm with my trim in and when doing 40 I was able to reduce the porpoising to almost non existant. Everybody was much happier.

I think I may go the smart tab route anyways. From everything Ive read there's no downfall and seems like lots of possible upside.

 

[JASinIL2006]

Other than the cost of having to buy them, the only downside I've seen to SmartTabs was about a 1-2 mph loss of speed at WOT. They totally eliminated porpoising and chine walking, which more than makes up for any losses.

 

[Wrekked]

I just received mine today. The boat is in the water for the season so I'll probably get the mechanic at the marina to throw them on for me at the same time. The rest of the year wifey wont be on the boat anyways so I can just cruise as needed.

 

[Captain Caveman]

Porposing can also be caused by extra weight in the bow. Asking people to sit in a different part of the boat may also help and reduce the need for smart tabs.

 

[Texasmark]

I believe I was somewhere around 5600rpm @ 55mph. I believe max is 6000 rpm. I was trimmed about halfway up. The water was very calm for this lake when I maxed it out (slight chop). The boat had no issues with 2 adults and 2 children in the boat and 2 children tubing at 25mph. But I did have 2 in the bow, me at the helm and the other adult in the back. In my scenario where I lost plane I had myself and my 2 year old at the helm and my 5 year old and wife in the back.

yes, I would try to bring the prop down. Maybe I didnt bring it down enough. Ill give it a try again today although the water seems calmer today. Was tricky with a sleeping toddler on my lap. So if I'm reading what your saying right, I really have 2 options, lose plane or go faster?

It also tends to porpoise around 35-40 mph which I am used to as normal. I assume theres nothing to be done about this without tabs as well? This doesnt bother us, just more curious. Its a weird spot that I can replicate time and time again. If I trim up just one or two slight presses it seems to reduce it by about half but anymore and I ventilate again.

You were stern heavy when everybody moved mid-ship to stern jump seats and cutting power to boot. Agree you didn't "tuck it in" far enough and apparently you didn't per your later remarks. To keep your 55 and get your comfort at lower speeds and can go the bill, I think smart/hydraulic trim tabs would be your answer. You want something to keep the stern up at slow speeds (using their bow lift) yet not introduce drag (trying to force the bow down) at high speeds, where bow and as much of the boat as can be, up out of the water....tabs that don't move would restrict that.....doing their job.

 

[Wrekked]

Delayed response here, but I bought smart tabs. I'll have them installed for next season and see how it goes. I have been out since by myself and I noticed that it can really get tossed in the air when going over bigger waves such as the last 3 waves of a wake, not something that bothers me really, but will the family. Not sure if tabs will help that part, I assume that's just how smaller boats are. Seems to pound off of waves rather than cut through them.

Other than that, we have been loving the boat. Glad I went with the 150hp, 115 would not have been enough. Had to run from a storm last weekend in the kawarthas so was nice to be able to run away at 45mph with a boat load of people and bow down a bit to handle the rollers.

 

[Texasmark]

The hull is the answer. The heavier the boat and deeper the V the softer the ride. Light weight, semi-V hulls, especially in the "Tri-hull type of boat will vibrate your teeth. My first family boat was the semi-V. Took me 1 season to get enough. Next season had a different new boat. A much heavier, deep V tri-hull and the difference was day and night and worth the financial beating I took in buying 2 new boats 1 year apart. Since then I ensured my boats had "dead rise" (measurable V) at the stern.

 

[Wrekked]

I have 19 degrees of deadrise but she roughly weighs only 2800lb with fluids and safety gear etc.

 

[Texasmark]

I have 19 degrees of deadrise but she roughly weighs only 2800lb with fluids and safety gear etc.

Since my biggest boat was 18', 19* and 2800# would be "Heaven" for me.