182 Captiva 4.3 porposing

[kleake]

I am fairly new to boating and just bought a 97 182 Captiva with the 4.3L.  So far we have had it out about 6-7 times and it runs great.  The only real "issue" I am having is with porposing.  On glass smooth water I can trim it out nicely, but on rougher water I can't get it to quit at all.  If I trim all the way down it does help, but I then hear a slight growling from the outdrive, so I know it's straining things a little more.  If I just bump the trim up, it quiets down nicely, but it starts porposing worse.   If I bump the trim up a couple of times, I feel a little surge of power, knowing the engine is working less, but the porposing also get much worse.  There is 4 holes drilled where the previous owner installed some sort of hydrofoil I am guessing.  I have heard good things about these, but am wondering how much one would help on this particular boat, and which one would work best.  Holeshot is already great, and it planes out pretty quick so that's not as much of an issue.  It also has a 19 pitch 3 blade SS prop on it at the moment.

[Capt Ron]

Usually porpoising is caused by excessive trim. On a cruiser you can stop this by adding some down tab or simply trim it down a bit. Try, playing with your trim to find that sweet spot that works for rougher water...

[kleake]

Usually porpoising is caused by excessive trim. On a cruiser you can stop this by adding some down tab or simply trim it down a bit. Try, playing with your trim to find that sweet spot that works for rougher water...

On smooth water this works, but on medium to rough water, I can trim all the way down and it won't stop.  When the trim is all the way down, I can hear a slight growl from the outdrive.

[DaleM]

kleake I saw in your other thread that you were bumping up against the rev limiter at 4600 rpm with the 19" prop, also that you were having a porpoising problem.  This is crazy thinking but could you be underpropped too much?  Meaning that with the 19" prop you're boat is lifting that front end too easily causing the porpoising problem.  Maybe try a 21" pitch.  Basically I'm thinking you shouldn't be hitting the rev limiter either.

[kleake]

kleake I saw in your other thread that you were bumping up against the rev limiter at 4600 rpm with the 19" prop, also that you were having a porpoising problem.  This is crazy thinking but could you be underpropped too much?  Meaning that with the 19" prop you're boat is lifting that front end too easily causing the porpoising problem.  Maybe try a 21" pitch.  Basically I'm thinking you shouldn't be hitting the rev limiter either.

I have thought about that too.  I don't usually run up that fast, so the lower pitch for hole shot is ok with me as long as it isn't causing the porposing.  If I am in a hurry, I will get up to speed until I hear the rev limiter, then back off just a touch till it isn't hitting it, but I never run there for any length of time.  Most of my drive time I don't run over 4000 rpm, but with the porposing, it's hard to get over 3500.  I don't know how much of a difference the prop would make with porposing,,, to me it's more of a gearing change for speed vs. power,,,, but I'm still new to boating so I could be wrong.

[mvn]

I had this exact same issue with our 192.  Prop issues aside, there are 3 devices that will cure your problem.  First is the hydrofoil, second is electro-hydraulic trim tabs and third is Nauticus Smart Tabs.  There are pros and cons to each.  I personally prefer the Smart Tabs.  Do a search on this site for more info.

[kleake]

I had this exact same issue with our 192.  Prop issues aside, there are 3 devices that will cure your problem.  First is the hydrofoil, second is electro-hydraulic trim tabs and third is Nauticus Smart Tabs.  There are pros and cons to each.  I personally prefer the Smart Tabs.  Do a search on this site for more info.

These are the options I have been looking at.  Trim tabs,, probably Smart Tabs,, I think would be best, but also most cost.  I'm thinking of a hydrofoil as simple and cost effective,,, but also there are several choices of those.  Some people say nothing but good about them, others say some good, some bad.  Any recommendations as far as brand?

[Titans_1]

I had a 182 - my issue was planing.  I bought the "Stingray" and it worked great for me.  A buddy of mine has one that's more curved on his 19' Maxum, he likes it.  I'm not sure of the difference in performance, but suspect it's not huge.
Be careful getting in the boat from the water, it'll scratch ya!  Also, you'll want to make sure you don't forget and leave your ladder down.  Been there, done that.  Caused a bent ladder.
West Marine sells em for $49.  Buy one, if it sucks, you're not out much!

[Dan&Darci]

I had a 182 - my issue was planing.  I bought the "Stingray" and it worked great for me.  A buddy of mine has one that's more curved on his 19' Maxum, he likes it.  I'm not sure of the difference in performance, but suspect it's not huge.
Be careful getting in the boat from the water, it'll scratch ya!  Also, you'll want to make sure you don't forget and leave your ladder down.  Been there, done that.  Caused a bent ladder.
West Marine sells em for $49.  Buy one, if it sucks, you're not out much!

What he said!  I've had very good results with hydrofoils.  Let us know if it works. 

[kleake]

Thanks for all the pointers.  I already have holes in the cavitation plate from the previous owner, and I found a foil on CL for cheap, so if it fits, it may be a quick fix, or at least an improvement.  I also was lucky enough to find an extended swim platform floating in the lake the other day that fits nicely, so if I can track down some brackets, that will go on.  I know this will add stearn weight and make the porpoising worse, but it will also move my ladder back, so I can put some trim tabs on and not worry about people hitting them all the time.   So, tabs will likely be the long term fix, and a foil for a quick cheap cure, or at least improvement.  Gotta do some hunting to find the brand of platform this is.  It looks like it slides down into some brackets and pins to keep it on.

[Titans_1]

Can you put a foil on with a swim platform?  On my 242 FV my lower unit trims so high, I'm afraid a foil would hit the platform.  If it's cheap, go with it until the platform is installed, but be prepared to possibly have to remove.

[kleake]

Can you put a foil on with a swim platform?  On my 242 FV my lower unit trims so high, I'm afraid a foil would hit the platform.  If it's cheap, go with it until the platform is installed, but be prepared to possibly have to remove.

That's a good question,,, and I'll have to look at that when I do the "mock up" of the platform.  I think I have plenty of room, but might be close in the full trailer mode, so if I have to leave it a little bit down I should still be ok as I have plenty of ground clearance now.

[kleake]

Well, I found a guy on Craigslist that said he had a Stingray that would fit mine for $25, so I headed over there and it turns out it was only the little stingray jr..  What he also had was the stearns hydrofoil that is two pieces and they matched up with the holes already in my cavitation plate.   I picked them up for $15 and figured I would give them a try.  There is a noticeable difference, but it didn’t completely stop the porpoising.  What it did do is lower my on plane speed by about 5-6 mph, and now when I move the trim it makes a much bigger difference.  So when it does start to bounce, I could trim all the way down and it would start plowing and stop the bounce, where before it would still continue.  Once it smoothed out, I could trim back up just a touch or two and be at a steady cruise.  It also made it where I can adjust the trim to corner differently, where it didn’t seem to do much before while in a medium speed corner.  Overall, the only real change is it gave me more control, rather than being at the mercy of what the boat wanted to do.  Worth the $15 for the improvement, but not a complete cure so I will still be looking to add the Smart Tabs.  And these don’t stick off the back so far, so the extended swim deck will still work with them.   I did lose about 2mph off the top, and I can see a definite change in the water flow behind the prop.

[randalstl]

I have a 98 model 182 with the same problem, I had ask 3 different dealers if I needed a hydrofoil and all 3 said no, It was porposing really badly, It was to the point I didnt want to use it when there was lots of boat traffic, It was beat me to death.
Yesterday my brother and I did research and decided to put one on anyway. It made a huge difference. It's at least 95% better, my knees never hit the dash in rough water.
I wish I had done this 3 years ago.

[kleake]

I am setting in a cove fishing with my boys as I post this. What a nice morning!  :-)

This is my first weekend with smart tabs instead of the fin. (I know, it took me a while to do it)  the fin made a very big improvement, so I hesitated on the smart tabs, but I am glad I made the switch.  I get up on plane much faster, even with a full load, the porposing is virtually gone even trimmed up considerably, and top speed has increased.  To compare, before anything I could hit the rev limiter at about 43mph on glass smooth water, with the fin I couldn't ever hit it, but could only get about 40-41 mph.  Now with the smart tabs I am boucing off the limiter at 43mph constantly if I let it.  I believe I want to try a 20 or 21 pitch prop now instead of this 19.  I caught the tabs on sale at iBoats for just under $100 a couple of weeks ago, and am very pleased.   Anyone who says a fin or tabs won't make a difference hasn't tried them on this boat.  I would say a fin fixes about 75% of the issues, where tabs fix 100%.

And welcome aboard, I am glad to see anothe little 182 on here!