i have a 14 lifetimer skiff. need advise on getting up on plane. boat comes with a 25 yamaha and boat porpoises a bit. i was thinking of a hydrofoil for the motor but maybe its as simple as 50lbs added to the bow . i tried a prop with a different pitch but the rpms were to high at the higher end of the throttle. any ideas?
hydrofoil or not
- Thread starter majt
- Start date
scott craven
Well-Known Member
if you're getting bow rise at hole shot, the foil will definitely help.
it will also help you stay on plane at lesser speed.
I would try one before adding weight, as additional weight will impede your overall performance.
it will also help you stay on plane at lesser speed.
I would try one before adding weight, as additional weight will impede your overall performance.
TheBigGuy
Well-Known Member
The trim wedges is great advice. If that doesn't do the trick you may have to resort to a foil.
As I have posted before that would not be my first choice. A foil can dramatically improve handling, but I've had instances where the foil has taken of the top speed and turning radius of the boat.
I think the key is to find the smallest fin available for your motor. They are hard to find, but I believe Atwood makes a small 2 piece fin that might work well for you. The ones I'm talking about are shaped with a bend inverted upward towards the tips of the fin. Once you are up on plane most of the fin isn't in the water. Less drag to reduce your speed and turning radius is supposed to be the idea of that type of design. I belive they make that model in two sizes, look for the smallest one for your 25hp motor.
Please don't bother posting about how you've never experienced any negative results from a fin (as happens every time I post this). I have experienced loss of speed and turning radius in several installs over the years, so it does happen. I would not post it, if I had not experienced that personally on several install over the years.
With a 25 on a lifetimer, which is a fairly heavy aluminum boat for the size I do not think he would want to sacrifice any speed. That is why I'm suggesting that he look for the smallest fin with the least amount of drag that he can find.
Just because this has never happened on your installation does not mean that a speed reduction from installing a fin does not occur. I'm trying to make sure he avoids this problem with his install, if he chooses to go that route.
As I have posted before that would not be my first choice. A foil can dramatically improve handling, but I've had instances where the foil has taken of the top speed and turning radius of the boat.
I think the key is to find the smallest fin available for your motor. They are hard to find, but I believe Atwood makes a small 2 piece fin that might work well for you. The ones I'm talking about are shaped with a bend inverted upward towards the tips of the fin. Once you are up on plane most of the fin isn't in the water. Less drag to reduce your speed and turning radius is supposed to be the idea of that type of design. I belive they make that model in two sizes, look for the smallest one for your 25hp motor.
Please don't bother posting about how you've never experienced any negative results from a fin (as happens every time I post this). I have experienced loss of speed and turning radius in several installs over the years, so it does happen. I would not post it, if I had not experienced that personally on several install over the years.
With a 25 on a lifetimer, which is a fairly heavy aluminum boat for the size I do not think he would want to sacrifice any speed. That is why I'm suggesting that he look for the smallest fin with the least amount of drag that he can find.
Just because this has never happened on your installation does not mean that a speed reduction from installing a fin does not occur. I'm trying to make sure he avoids this problem with his install, if he chooses to go that route.
triplenickel
Well-Known Member
Got it, only one opinion and set of experiences allowed in this thread. Mods please close it.
TheBigGuy
Well-Known Member
Ha ha.
What I was trying to get across is that just because that might never have happened in your install, does not mean it doesn't happen. Just as it happening with me does not mean, it will happen in every install. A bunch of guys saying it never happened to them does not negate the fact it could happen in this case. I was merely trying to give him some good cautionary advice. A bunch of guys saying that doesn't happen, doesn't mean it's not a possibility. But if a bunch of guys want to post that it has never happened to them fly atter. Doesn't change the fact that it could happen.
Better to listen to someone who's experienced this issue personally, than pretend it never happens.
the motor is set up right i believe. i moved the gas tank to the middle of the boat and trimmed the motor in on the last hole.. made a difference most defiantly. the motor has no lack of power and speed. i only run it at 3/4 throttle. with the new trim adjustment , i have to watch the back wash when i slow down.
thanks for all the info, see you on the flats.
thanks for all the info, see you on the flats.
ReelSlim
Crew Member
I have a 15' Silverstreak with a 25Hp Yamaha long shaft......so pretty much the same set up as you. I did have to go in a notch but not all the way if I remember right? I'll double check in a few days when I'm back on the coast. I have a small flat floor section in the bow that I keep a tote with my anchor and safety stuff etc. and it seems to ride very well without adding any useless weight. It still might be a tad light in the bow when I'm solo so I had considered keeping the 2.5Gal day tank that came with the outboard. Good to have the extra gas anyways.....imo. 
I do have a foil on my bigger boat and I like it on that set up.......for what it's worth....lol I do think with a tiller style boat you can get the results you want doing a few things that have been suggested.....good luck!
I do have a foil on my bigger boat and I like it on that set up.......for what it's worth....lol I do think with a tiller style boat you can get the results you want doing a few things that have been suggested.....good luck!
sly_karma
Crew Member
I put on a hydrofoil on my J140 a couple months ago. I'll keep it on for an upcoming trip but think it will go after that. The problem is reduced fuel economy and reduced top wend speed, both I presume from added drag. It does keep the boat on plane longer, and for that reason I will keep it for a trip into Sechelt Inlet later this month. Reducing speed below 19 mph in choppy conditions causes the stern to drop and the boat plows through the water and gobbles fuel. The hydrofoil has eased that issue, now I can go as low as 14 mph before the butt drops and the fuel use jumps up. But my top speed has dropped from 39 to 35 mph, and best cruising fuel mileage is down from 4 mpg to 3.5 mpg. It's a tradeoff. Fortunately it's pretty easy to remove/replace so I might resort to leaving it off for my Okanagan days and reinstalling before longer coastal trips.
I have a older 15 Lifetimer with a 50 Honda .I had to trim in all the way to keep the bow down. Talked to Lifetimer and they recommended adjusting the internal trim tab on the bottom of the transom by bending it in small steps. Didn't work so went with Smart tabs. They worked but I still had to trim in all the way but I could keep the rpm down and stay on the step. Wore out 2 sets of actuators on the Smart tabs so took them off last week and put on a Stingray to try. Works great. Better control with a load, lower rpm at cruise and wot is still 5800. Still playing with rpm and mpg to find the sweet spot but so far so good. I used to get a puff of smoke at startup in the morning sometimes If I forgot to trim up when I shut down , now it's always trimmed up so no more smoke. Not as much turbulence around my P66 at speed with the Stingray as with the tabs.
took boat back to lifetimer when new and banged down the internal tab. helped a bit . had the motor on second to last trim setting(in). still porpoise and hard to get on plane. moved trim to all the way in and big difference. lower rpm to plane and rides exactly the way it should on a plane whether in chop or lumpy. not sure trimmed all the way in will do when another person is in the boat . any ideas? i
will get that bar for quick adjustment of trim rather than the 2 bolts on motor now. ive heard so many mixed reviews on the stingray.
will get that bar for quick adjustment of trim rather than the 2 bolts on motor now. ive heard so many mixed reviews on the stingray.
Whole in the Water
Well-Known Member
Another nice reason for a hydrofoil it is help deflect line away from the prop a bit as well.
SpringVelocity
Crew Member
Put hydrofoil on. Your butt heavy in that boat. Only other way is trim tabs. I have one on my boat and highly recommend them. It will push bow down and also allow you to get up plane in lower rpm.
here's a follow up....i installed a doel fin set up and trimmed the motor back to the second setting out , the same as lifetimer suggested. this was the setting that gave me some issues re porpoising and slow to plain previous to installing the fin. prior to the fin. i trimmed the motor all the way in but had some concerns. i had also placed the gas tank in the middle of the boat for better weight distribution but that lessened the space in the boat. trimmed all the way in, the boat preformed the way i wanted it to do but i wasn't satisfied so i installed the fin. i also put the gas tank at the stern and freed up more space. so the set up with the fin was trimmed on the second setting and the gas at the stern. with the fin, the boat preformed well. it got out of the hole to a plane great and there was no porpoising at all. so i would recommend the fin. it was stable at high speeds and no issues re steering. all in all it seems to have solved the issues for 50 bucks.....
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