Boat handling Saftey Issue

[fishon396]

OK, first question, Do you have a torque steer tab right above the prop and do you have it set to the side to correct torque steer? What you are describing as Kick Out sounds like the torque steer tab finally coming clear of the water at that specific speed as the boat rides up higher on the pad. It suddenly clears the water and the force it is putting on the engine is released and you feel a tug to the side. You should also get the same effect to a slightly lesser degree when slowing back down thru that range. You have the engine mounted very low so this corresponds to a higher speed. Raise the engine and it will occur at a slower speed. The torque steer tab is a less than perfect solution and has this drawback. This is why most running a superior steering system like hydraulics remove the tab entirely.

Next is the skittish feeling of this specific engine at higher speed. It is because you have your engine mounted too deep. The foot and housing of this engine is not well hydrodynamic above 45 mph. It starts to oscillate or shake the engine side to side. Yes I know you went deeper to fix the blowout. That is a Band-Aid fix to another problem. You need a prop with more cup and better slip numbers. The laser II has no cup and three blades. It works OK in clean water off certain hulls. Others it looses its grip on the water easily. You need a better prop and raise that engine back up to 4 inches or less under the pad. That will resolve the skittish feeling by getting more of the casing and foot out of the water. A good prop for your standard gear case to allow you to run your engine higher would be the Spitfire X7. This is precisely what I had to do with my engine to correct the same steering issues. Spitfire X7 prop running at 3.5" and steering problems disappeared.

There is a good chance this is your answer.

[OBT]

Will respond more after I get home from work but skeeterbait May have come up with the answer!

[OBT]

OK, first question, Do you have a torque steer tab right above the prop and do you have it set to the side to correct torque steer? What you are describing as Kick Out sounds like the torque steer tab finally coming clear of the water at that specific speed as the boat rides up higher on the pad. It suddenly clears the water and the force it is putting on the engine is released and you feel a tug to the side. You should also get the same effect to a slightly lesser degree when slowing back down thru that range. You have the engine mounted very low so this corresponds to a higher speed. Raise the engine and it will occur at a slower speed. The torque steer tab is a less than perfect solution and has this drawback. This is why most running a superior steering system like hydraulics remove the tab entirely.

Next is the skittish feeling of this specific engine at higher speed. It is because you have your engine mounted too deep. The foot and housing of this engine is not well hydrodynamic above 45 mph. It starts to oscillate or shake the engine side to side. Yes I know you went deeper to fix the blowout. That is a Band-Aid fix to another problem. You need a prop with more cup and better slip numbers. The laser II has no cup and three blades. It works OK in clean water off certain hulls. Others it looses its grip on the water easily. You need a better prop and raise that engine back up to 4 inches or less under the pad. That will resolve the skittish feeling by getting more of the casing and foot out of the water. A good prop for your standard gear case to allow you to run your engine higher would be the Spitfire X7. This is precisely what I had to do with my engine to correct the same steering issues. Spitfire X7 prop running at 3.5" and steering problems disappeared.

1) Do you have a torque steer tab right above the prop and do you have it set to the side to correct torque steer? Yes, and its in a neutral position, not angled to one side or the other.

2) What you are describing as Kick Out sounds like the torque steer tab finally coming clear of the water at that specific speed as the boat rides up higher on the pad. It suddenly clears the water and the force it is putting on the engine is released and you feel a tug to the side. You should also get the same effect to a slightly lesser degree when slowing back down thru that range. Makes sense and sounds 100% right. As for feeling it to a lesser degree when slowing down. I think you're right here as well. I remember it happening but I've been so focused on the other that I'd forgotten all about it so I'd call your point "confirmed".


3) You have the engine mounted very low so this corresponds to a higher speed. Raise the engine and it will occur at a slower speed. The torque steer tab is a less than perfect solution and has this drawback. This is why most running a superior steering system like hydraulics remove the tab entirely. Interesting, "Remove the Tab altogether?This also make sense and I agree, especially based on everything I've ever heard. I'm planning on a Hydraulic System, I just have to find out which for my set-up.

4) Next is the skittish feeling of this specific engine at higher speed. It is because you have your engine mounted too deep. The foot and housing of this engine is not well hydrodynamic above 45 mph. It starts to oscillate or shake the engine side to side. Yes I know you went deeper to fix the blowout. That is a Band-Aid fix to another problem.

I agree again, but I got this from Mercury this past week and it threw me for a loop "These four-stroke engines like to sit much lower in the water than a two-stroke, so you will likely need to drop the engine as low as possible. This should help with the issue of blowing out, and may help with the handling of the boat as well." Goes against everything I've ever read.

5) You need a prop with more cup and better slip numbers. The laser II has no cup and three blades. It works OK in clean water off certain hulls. Others it looses its grip on the water easily. You need a better prop and raise that engine back up to 4 inches or less under the pad. That will resolve the skittish feeling by getting more of the casing and foot out of the water. A good prop for your standard gear case to allow you to run your engine higher would be the Spitfire X7. This is precisely what I had to do with my engine to correct the same steering issues. Spitfire X7 prop running at 3.5" and steering problems disappeared.

Good news indeed. The Spitfire X7 was one of the choices given to me on Mercury's Prop Selection page. I found a site that sells these, but the specs are a little confusing as to whether they have one that fits the "Standard Gear Case 14x29 2.07:1" so i still have to review the site and its selections when I get more time! (Work keeps getting in the way!)

Also, I run the 20 pitch (13 1/4") now because it gets me to the recommended 6300 rpm for that engine. (6350 rpm actually on Vessel View) I'm seeing that One - The Spitfire X7's are 4-bladed and in 19" pitch and 21" pitch. I'm going to order one, but which? https://www.boatpropellerwarehouse.c...28/spitfire-x7

These are the two I'm looking at. I notice that the diameter is smaller than the three blade. Might be part of equalizing performance with three blades? (Drag, engine load etc)

https://www.boatpropellerwarehouse.c.../8132/21-pitch

https://www.boatpropellerwarehouse.c.../8131/19-pitch

Skeeterbait, Thank you. Every single thing you've said makes sense and has confirmed some of my thoughts and helped me tie together the mangled remaining ones I've been having. Same for all the other contributors too, thank you. Any other suggestions are welcome!

[Boatseller]

All Triton's IMHO with 115hp and above should have a jackplate. You can work out 95%of your problems.

[OBT]

All Triton's IMHO with 115hp and above should have a jackplate. You can work out 95%of your problems.

I agree and getting one has been on my mind for a long, long time. Things just keep coming up. Boats are expensive ain't they! Maybe its time to bite the bullet. After all, if I'm going to take it in to get it raised, I might just as well have them install a jackplate since the engine will be off!

[Skeeterbait]

If you are going to go to the expense of hydraulic steering that will fix your kick out issue. It will likely improve the skittishness feeling by locking down the engine and not allowing it to oscillate, shudder side to side. It will be an all around improvement compared to the slack in cable steering. You should then be able to cut off the steering torque tab or buy the filler disc for the engine that has no tab on it. I recommend just living with the kick out for now because hydraulic will make a world of improvement.

I am not sure which pitch you will need of the Spitfire X7. I tried a 19 and a 21 and found the 19 to allow just a bit too much RPM on my non-ProXS model. The 21 just felt a bit sluggish when I had a large partner with their gear onboard. These small boats are weight sensitive. I am suspecting that your fiberglass, with a pad, and raising the engine a bit, and your Pro XS which is supposed to have a bit more torque, may enable you to run the 21P, but don't hold me to it. Realize that a Laser II when it is running right, will likely exceed the Spitfire X7 by a couple mph. But the Spitfire X7 is going to give you steering control the Laser II will never give you. Yes the smaller diameter is because of the 4th blade and cupping and trying to keep the pitch matched on a performance scale. And your standard gearcase is the same as mine. The hub diameter is the same. Check prop prices on http://jacosmarine.com/

Mercury's advise makes sense if you are determined to stay with the Laser II, making the best of a less than optimal situation. But raising the engine makes better sense with a better prop. The addition of a jack plate, even manual will even improve prop performance a bit by setting the engine back a bit from the hull. But it will also enable you to easier experiment with different engine heights making the adjustments yourself. I have hydraulic, expensive but you can learn optimal settings for different conditions and make changes as conditions change throughout the day. Shallower in smooth water and access to shallows, deeper for control in choppy water.

This is the height I run in smooth water, 3.5". I drop to 4.0 or 4.5 in chop. You have a step hull with pad. You should be able to run your engine much more shallow than you are currently.





Here is a video of the Spitfire X7 running at 3.5" This is trimmed a bit higher than optimal, but the point is this prop does not blow out.

[n2ratfishin]

Cut that tab off flat and install a after marke torque tab on the starboard side of the skeg. Quite sure this will improve things

Those torque tabs come off too easy. Back in the day, before NFB steering, I had them on my 175 Rude mounted on a 17' Hurst (Wrangler knockoff) we only had single straight cable steering back then. That thing was a BEAST to drive! You would have arms like Popeye after about a half hour run LOL. I fished the stumpy shallow waters of Santee Cooper back then and I bet I pop riveted another torque tab on every six months.

IMO His answer is in engine height and prop.

[lpugh]

Those torque tabs come off too easy. Back in the day, before NFB steering, I had them on my 175 Rude mounted on a 17' Hurst (Wrangler knockoff) we only had single straight cable steering back then. That thing was a BEAST to drive! You would have arms like Popeye after about a half hour run LOL. I fished the stumpy shallow waters of Santee Cooper back then and I bet I pop riveted another torque tab on every six months.

IMO His answer is in engine height and prop.

1. Installed correctly they will never come off. Drill and tap the skeg for 8/32 machine screws (countersink type) sand the paint off the skeg in the mounting area, apply marine tex to the mounting surface and attach the tab with screws. Use marine tex to blend it in, when dry blend and shape to smooth things out and paint with a high quality black etching primer. A good primer will not peel chip or crack and is very easy to touch up
2. Not likely though it may be improved

[OBT]

Thanks Skeeterbait.

Update - Got on the phone with Mercury today to talk with them about the email they replied to were they suggested, "These four-stroke engines like to sit much lower in the water than a two-stroke" and told them that's its 5.25" below pad already and that seemed 'too low'. Also told them about the general feeling that the Laser II prop was mostly likely the cause of the problem of the WOT prop Blow-out. They agreed, adding that the Laser II while good, didn't have the cup I needed and that the Spitfire X7 4 bladed prop was the right way to go and that I could easily raise the engine back up again.

Next, I was finally able to talk with the "right" guy at the Triton Dealership where I got both the boat and later the new engine. He agreed with the prop choice and raising the engine back up and was very familiar with the boat's tendency to "kick-out" at the mid range speed. First thing he asked was if I had cable steering and said to go Hydraulic steering saying that when it happens with the Hydraulic system I probably won't even notice. Apparently the play in the cable steering is the thing that makes the kick out worse. He also agreed that throwing a Jack plate on at a later date wasn't a bad idea.

So, the boats at the dealership getting raised and the new prop will go on as soon as I get it. Hopefully before I leave on my vacation this weekend! Soon as I can, I add another update as to how the boat runs with the new prop.

[sabby]

Put a manual jackplate and a 4 blade prop on. Adjust height in small increments, the problem will go away and you will have better performance.

[OBT]

Update - Got the new Spitfire X7 4 bladed prop (12.7 x 21") installed and the engine raised back up a hole to where it had been before. What a difference. No more prop blow out at WOT. Speed still good and no back end kick-out. Hole shot is good to. It was worth the trouble. Next on the list is Hydraulic Steering and then maybe a Jack plate. Thank you all for your suggestions and ideas!