boat motor height?

[Jigaman]

I have a 1999 lund 1850 tyee w/ 135 optimax. Although I wish it had a bit more power it does alright for our family. Once I get it up on plane I can trim it quite a bit and IMO it handles well. My inlaws have a 2014 lund crossover 1875 w/ a mercury 150 4 stroke. boat has plenty of power but I am wondering if the motor is too high. I can barely trim it up before it blows out but what is really noticeable is when I am pulling the kids on the tube you cant turn nearly as sharp as I can with my boat before the prop starts to blow out. I always pull the tube with the motor trimmed down all the way. If I lowered the motor one hole on the crossover would that improve things? Man I am ready for summer.

 

[SDMF]

SS or AL prop?

 

[Jigaman]

AL on the crossover

 

[JCNodak]

I dealt with this last year on my new Impact 1850 XS. It has the same hull as the Crossover and I have the same motor. My motor was already all the way down. I had a 19p aluminum prop from the factory. Same thing. When I trim up so the side spray is behind the driver's seat, any turning and you blow out. I tested a 19p SS prop and a 21p Al prop. Setteled on the 21p al. I didn't notice any real difference from al to ss. It got a little better with the 21p prop. I think it is just inherent of that hull design. Nothing I have done corrects the problem. I chalked it up to learning my new boat. Now when under way, I have my thumb on the trim tab and have learned to trim down when going into corners. If the motor isn't all the way down, it could surely help. It helped on my buddy's impact but that's a 17.5'. Best of luck.

 

[Jigaman]

thanks JCNodak, I will look into trying a different prop. Maybe the motor is in the lowest hole already like yours is. I havent looked. Normally I wouldnt really care about someone elses boat this much but I am hoping to buy it in a couple years if they upgrade since I really like this boat. Good compromise since I love to fish but my wife and kids are more into boating/tubing/swimming.

 

[JCNodak]

thanks JCNodak, I will look into trying a different prop. Maybe the motor is in the lowest hole already like yours is. I havent looked. Normally I wouldnt really care about someone elses boat this much but I am hoping to buy it in a couple years if they upgrade since I really like this boat. Good compromise since I love to fish but my wife and kids are more into boating/tubing/swimming.

I hear you Jig. I bought mine at a boat show. I was initially going there to look at a crossover. But the Impact XS really changed the game for Lund. It has the creature comforts such as jump seats and a ski pole and a swim ladder. But where it wins are a couple of areas. First there is way more storage for fishing gear. The rod locker holds 10 instead of 5 rods plus you get two live wells, not that I use the front one. I felt like I was sitting up higher in the Impact. I thought I would not like the side boxes but the additional lockable storage is really nice plus there is room for more rods. I don't know about the corssover glove box but the Impact's is HUGE!. The package deal I got on the Impact was a better deal than the crossover. I guess I am just saying I am happy with my purchase. I guess I would have been also with the Crossover but I have never been in one on the water so I couldn't say. I think the Impact is a little more geared towards fishing still maintaining the family watersports aspect. Like I said, the prop didn't affect the performance too much. I think the 21p took a bit away from my hole shot. But the 150 has plenty of giddyup so it doesn't really matter.

 

[ndlongshot]

I have a similar set up. My boat almost makes me nervous as I try and kick it down across the lake. When i hit that trim up, man does it come out of the water. Almost feels like its borderline squirrely/out of control feeling. I guess I just figured it was due to way more motor then I was used to.

 

[Jigaman]

glad to see that I'm not the only one with this issue and it's not all in my head. I have been trying to find more info online with no luck.

 

[ndlongshot]

Jiga,

Either its normal, or we need to grow a pair! Not sure which! ha!

 

[JCNodak]

I have a similar set up. My boat almost makes me nervous as I try and kick it down across the lake. When i hit that trim up, man does it come out of the water. Almost feels like its borderline squirrely/out of control feeling. I guess I just figured it was due to way more motor then I was used to.

I totally understand the squirly part. Usually I tap the trim up until you feel it almost break loose. The steering goes from stiff to easy. That's where I stop.

 

[shorthairsrus]

put a stainless on it -- it will hold onto the water better -- it wont blow out plus you will gain some speed. Merc has many choices

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if she is loose -- -she is fast

 

[Captain Ahab]

Try a 21p "high five" prop if you can get your hands on one. It really made my dad's old Tyee "stick" and get out of the hole.

 

[eyexer]

just make sure you can reach max rpm with a light load when at wide open throttle. if you can't your over propped. and that will also cause blow outs.

 

[SLE]

A handfull of things to think about with boat set up and I've owned a few in my life at this point and alway strive to push the performance limit; First thing is first, not all hulls are created equal even within the same brand and model, some just run-out a little better due to slight variations in hull deflection, cupping, loading, and other factors that come to play in the manufacturing process. If you don't have a jackplate, typically on a deep v walleye boat having the center of the prop shaft 3.5"-4.0" below the bottom of the boat is optimal. At 50 mph, every additional inch of your lower unit that is in the water is said to create approx. 1000lbs of additional drag, the higher you can run your engine without the prop blowing out (when running straight), typicaly the better (I run mine as high as 3"). Running the enigne in too low of a position will create all kinds of performance related headaches. a quick easy way to assess this is when your running at WOT, look over the transom and see if the water is below the cavitation plate, it should be, if not your likely set to low. Next, if your running over 40-45 mph and still using an aluminum prop, your missing out. Aluminum will flex and simply cann't be shaped the same way a stainless prop can be. Even a stainless right out of the box will hold the water way better than a similar aluminum prop. Also, not all stainless props are created equal, you will need to decide what performance characteristics you want and then choose a prop. There' are different blade styles, numbers of blades, diameters, location of cupping, barrel lengths, barrel flare, and other things that will give each prop it's own character. Bottom line, the most effiecient (typically the fastest) normally has the fewst number of blades and the highest pitch where your engine will attain the max rated RPM (this is a general rule). To get the best performance, under a light load you should run right against the max rated rpm for you engine, under a heavier load, hot or humid conditions, RPMs will drop. I personally run two different props, a DAH modified 21P Tempest Plus and a DAH modified 19P Revolution 4. These are two completely differnt animals, the Tempest is about 5 mph faster than the Rev but the rough water water handling and load carrying ability of the Rev 4 is night and day different. When loaded light I have to watch the RPMs to not over rev with the Rev 4. I've ran High Five's and they kind of have a place but there are better wheels out there, deffinately not the most effiecent prop I've ran and reverse was horrendous. I've ran no less than 9 different props across two boats so I've tried pretty much all the big hype props, some work, some don't. If you get the boat optimally set up, as you trim up the steering effort will loosen, continue to bump up the trim up untill rpms began to raise but the speed doesn't or begins to decrease, then bump the trim down just a notch or two. This will be your fastest trim setting. Normally on any hull with any performance, you'll need to trim back down to make any harder corner without the prop loosing grip and blowing out, this is completely normal. Being a little squirely at WOT is fairly normal but with a prop change you'll find this will change also.

FYI, spray and rooster tail will vary between boat and prop. With my Yar-crafts, when trimed out and running, the spray is at the back corners of the boat, and even inside the back corners if I'm light and really getting after it. On my skeeter, I couldn't ever get the spray behing the drivers seat no matter the engine height, prop, or loading of the boat, it just didn't matter. It also wasn't a very fast hull comparitively and I chalk that up to not being able to get enough of the boat out of the water. Take it for what it's worth.

Ideally, you'd have a jackplate on the boat and 15 different props to try sitting at the dock but we don't live in an ideal world and this stuff add's up $ in a hurry. I would start with the engine height (it's freebe if you do it yourself) and then dial in a good stainless prop to reach the max rated rpm of your engine. Used props can be found for $300-$400, new ones typically $550-$800. If you really want to get crazy, start weighing what you have in each compartment and move stuff around to attain the best weight distrabution or call a custom shop like DAH or Mark Croxton and they'll get you dialed in for the right $. A few props to consider and research are the Tempest Plus, Revolution 4, Bravo 1 FS, and or possibly an Enertia (All Mercury wheels).

Good Luck,

 

[Captain Ahab]

If all else fails, buy a Ranger.

 

[SLE]

Sorry for the long post, I get going on boats and well..... ahhhh, I don't usually know when to stop, lol.

 

[westwolfone]

Make sure you check out walleye central. They have many pages of boat discussions.

 

[Jigaman]

Sorry for the long post, I get going on boats and well..... ahhhh, I don't usually know when to stop, lol.

Really good stuff SLE. I just thought of something else, the blowing out while pulling a tube seemed to be much more of an issue after the AL prop got dinged up pretty good on some rocks. Maybe that is causing the problem? It did it before but not as bad as it does now.

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If all else fails, buy a Ranger.

someday maybe. The money trees I planted are not growing as fast as I hoped they would.

 

[JCNodak]

SLE-
When I got my boat it came with the motor all the way down and a 19p AL prop. This is my first boat that has power trim. I immediately tried to trim up so the spray was way back and that's when most of the blowing out occurred. I did the whole song and dance testing a 19P tempest plus and a 21p al. There was no noticeable difference to me. So now my cruising speed spray is just behind the driver's seat and the anticavitation plate runs right at water level. I think I have it dialed in the best it can be. Any advice there?

 

[SLE]

Absolutely on the dinged up prop, get it fixed or replaced and it will likely help. It doesn't take but a few minor dings and chips to knock it out of balance and or tweak the shape and cupping which will affect the performance in one way or another. Honestly, you really should look for a good used stainless prop. I would start with an Enertia or Tempest, both will be an improvement over the aluminum that you have. Watch the walleyecentral swap board, usually a some decent deals on props show up there in the spring as guys dig there boats out and start looking for the latest and greatest. When buying used make sure it isn't dinged up and hasn't been rebuilt (lots of prop hacks out there).

How many RPM do you run with the 19P at WOT and with the 21P at WOT?

Also, just for reference, I have to keep my engine trimmed down when pulling the kids around to keep mine from blowing out, this is pretty typical. It's especially noticeable when I have the jack plate set high. When the jack plate is lower, it's certainly less of an issue. You'll have to find the right balance between prop and engine height, there's no perfect setup, there's always a little compromise between handling, hole shot, and top speed, hence why I have two different props.