Stabiliser Fins -Stingray Hydrofoils etc

[NAGG]

Do you have any scope to adjust the front to back weight NAGG, to my way of thinking the boat should be balanced right then trimmed to push the stern forward rather than up or down.

I actually have a fairly well balanced out boat - particularly with a 60kg (200amp) battery plus anchors stored right up the front ........ ice box & tackle is stored just forward of center - so it's not to bad on that front

Chris

[Sevric]

I think most alloy boats suffer to some degree with trim problems due to their light weight for the surface area they occupy. I had my local dealer install a stingray fin to my 40 etec / 4.4 seajay and he said nothing about it voiding warranty. Since then the power trim unit has been replaced under warranty so i assume there is no issue but it would be wise to ask you dealer first. Perhaps have your dealer install the fin if you decide to go that way; it may make them see future warranty claims in a different light knowing that they sold and installed the unit. The stingray fin has done an excellent job since installation although i did loose a little top end speed. I think this happens with them all no matter the brand or the claims they may make to the contrary. As for increased fuel consumption well i do not think you could even measure it in my application so it has not been an issue. The only other consideration would be trim tabs which while expensive do a great job i believe; better than any of the fins.

[murf]

mmmm about to bolt on a Permatrim before my next outing, just did all the speed and hole shot tests before, I have a 5m 22deg very heavy in the arse end 1/2 cab FB boat

tried everything before including 6deg wedges so will be interesting to see the results, cav plate is 65mm above bottom of boat atm but does not ventilate unless I am in the river on a full tight turn with the kids on a tube as you would expect from a ski boat in tight turns

looking forward to the results and hoping it does what I need

will report

cheers Murf

[Screamin Semen]

I just fitted a SE Sport 300 that I purchased from "Floating Rib" Ausfish member, on my Yamaha 40HP ....he posted it to me very fast and was a great price...will let you know how it goes once this weather clears and I can water test it.

SS

[Crocodile]

Hello Nagg,
I have recently replaced an older 60hp 2stroke Yamaha with a new one.
Same motor but a new model.
I changed from a foil to transom wedges.
1. the dealer clearly said that the foil would void the Yamaha warranty.
2. transom wedges work better than a foil for low-speed planing.
As for porpoising couldn't say as it was never a problem before the change.
Pros for wedges;
1. better low-speed planing
2. warranty still OK
Cons
1. torque steer at extreme down angles
(managable, but very noticeable through the wheel, don't travel at that setting for very long)
2. a little bit more exhaust noise(I think that the foil smothered the exhaust sound)

[Jarrah Jack]

I'll be keeping a weather eye on this thread and look forward to Murf's report. I've got a F115 on my 520 sig and I reckon it could do with a foil. Doesn't bother me drilling holes in my 40 hr motor.

Interested to know why the yami stainless prop should be got rid of. In an ideal world I'd be trying props, wedges and a second wife but its not an ideal world.

[bigjimg]

I've got a Stingray XR fitted to the Opti and the difference is excellent.No holes to drill either and fits in a matter of minutes.Bow lift is almost nonexistent and the boat feels as though it is thrust forward in a staight line onto the plane.I fitted it purely for when we tow the kids on the tube and they only want to go slow,works an absolute treat.I didn't want to drill holes either,this foil is held in place by the anode under the cav plate.Worth a look.Jim

[Seahorse]

Can someone please fill me in on these wedges. I have seen them mentioned a few times on this thread.

I mainly put permatrim on to keep the nose down when do low speed, but not happy with it in fairly choppy seas.

Cheers
Greg

[NAGG]

Hello Nagg,
I have recently replaced an older 60hp 2stroke Yamaha with a new one.
Same motor but a new model.
I changed from a foil to transom wedges.
1. the dealer clearly said that the foil would void the Yamaha warranty.
2. transom wedges work better than a foil for low-speed planing.
As for porpoising couldn't say as it was never a problem before the change.
Pros for wedges;
1. better low-speed planing
2. warranty still OK
Cons
1. torque steer at extreme down angles
(managable, but very noticeable through the wheel, don't travel at that setting for very long)
2. a little bit more exhaust noise(I think that the foil smothered the exhaust sound)

Thanks Croc

I've sent a email to my Yamaha dealer to confirm any issues with warranty if the cav plate is drilled ........ I have a feeling there would be

I need to find out a little more about the use of wedges ......... anyone got photos ?

Chris

[spelchek]

FWIW, Nagg - I put an SE sport 300 on my 40 yammi/4.4 seajay and it made a world of diferrence to the boat. Much better holeshot, slower planing speed and less cavitation in following sea. I asked Bunday Marineland about the warranty on the yammi and they said (other than issues directly related to drilling the cav plate)that it wouldn;t void the warranty (ie if cav plate cracked or somhow 'fell off' it wouldn't be covered - but if, say, fuel pump died it would).

[Horse]

I tried motor movement and fitted 6 degree wedges but the only thing that worked was fitting a SE 300 foil. The boat feels like it is on rails. The wedges are especially important on older hull as modern tilt/trim motors do not have the range of movement the old manual tilt motors did so they can't trim in enough. Modern transoms have much more angle built in

[Screamin Semen]

I asked my dealership 'Marine Tune" about any warranty issues if I fit the SE 300...I was told it DOES NOT affect you're warranty at all.

[Kondo 1]

Kondo......maybe 5 degree engine wedges will help your problem?.......a mate has the little 415 territory with a 40 suzy 4strk on the back in tiller and his rig is a PITA with porposing ,he won't buy wedges as he is a tight@arse and wants to lug around 30ltrs of water up the bow to fix it.

Dan

GDay Dan,

I will probably give that a go - Mine actually isn't too bad at all porpoising with the right propeller, I just had to re-adjust my driving style to use less out trim than I was used too. The hull actually works really well once I got my head around it it just doesn't need allot of out trim at all.

Getting out of the water isn't actually too bad either now - well with the F70 anyway, different story with the F50... However slow paning in the slop is a bit of an issue still, overall it behaves well but I am always looking for the best I can get it.

I think the F70 is at least as smooth as the F50, certainly when you are right up it it is a little more throaty but it isn't intrusive, just sounds like it is breathing a bit better that's all.

[Kondo 1]

Interested to know why the yami stainless prop should be got rid of. In an ideal world I'd be trying props, wedges and a second wife but its not an ideal world.

Gday JJ,

To date I have tried 5 differnt props, with and without the permatrim and all the engine heights and I think I have it close to right, however slow planning in the slop could be better, other than that it is very well behaved.

One of the props I tried was one of the new Yamaha performance series S/S props, in my application it was terrible... Whilst it spun up reasonably quickly (probably due to the Ventilation holes) It's top speed was down but most of it have me far too much bow lift and as a result was extremely trim sensitive and was very prone to porpoising. This was possibly exacerbated by the need to trim out a little (not as much as the other props) to remove some of the prop torque I was experiencing and in turn there was a never ending chase going on where I would trim little by little to reduce the torque and then when it would porpoise it would require almost total in trim to remove the porpoise, and then starting all over again.

Certainly the F70 is a pretty big motor to hang on to with a tiller, and the effect is probably amplified by the much increased size of the prop on the F70 vs the F50&F60 however prop torque isn't really an issue using any of the other props I have tried especially as you can find the balance of trim to almost totally remove the torque felt at cruise.

Perhaps on a forward steering boat or some thing that needed some bow lift it would probably be a great prop, it just doesn't suit my application... And given I ever so slightly clipped a sandbank on the way back on the third test run (no damage just some ever so slight scratching to the face of the blade) I couldn't return it

To date the best I have found on my boat is the SOLAS 14" SS prop, its pretty good, certainly less slip than the Yamaha standard alloy prop in the 15" but at $500 a throw it isn't that much better than the $100 yammy props thats for sure... I reckon it probably does 80-85% of what the Stainless prop does and where I am generally stuffing around I am pretty happy to bin a few Ally props at $100 a pop.

[NAGG]

I was told yesterday by my Yamaha dealer that the installation of fins (bolt on) would not void the warranty unless you cracked the cav plate
The dealer also recommended the "fast tail alloy stabiliser" proven and tested with Yamaha motors. It looks pretty good as it bolts on from the underside of the cav plate which would distribute load better.

Chris