Motor Height

[ifishwalleye]

I have a 2008 WX2100 Skeeter with a 250 4 stroke with a Mercury Rev 4 19 pitch prop and a 9.9 kicker and a bow mount. I haven’t had this Boat for a very long time and I’m getting used to it. Oh, if it matters, the motors are Yamaha. Overall, I really like the Boat, however I have a few questions about motor height and how it effects the way the Boat handles. The motor is currently mounted in the 3rd hole from the top. There is only one more hole to move the motor up. The bow rides high even when the motor is all the way down with zero trim. Sorry for rambling but I want to provide as much information as possible. Top speed is 50 mph on the gps. I once say 52. I realize that this number seems slow and it’s most likely due to the 19 pitch.  At wide open, I am hitting 6k rpms. The reason why I have the 4 blade on is because I like to have the get up on the waves if they are rolling!

What I do know is that this Boat has a reputation for having balance issues due to the separate fuel tanks. 64 garland total!  What I have experienced is that when it rides good, it’s really good and when bad, it’s really bad. 

I am not a novice boater but I surely don’t consider myself an expert either. So the questions are as follows:

1) unless I’m going 40 mph or more I’m not able to trim the motor. At slower speeds if I do trim, the Boat porpoise really bad. 

2) at a cruising speed of around 30 to 35 if I watch how high the motor is running, I am not able to see the cavitation plate. It looks like it is at least 4 to 6 inches minimum below the water

3) if I’m traveling below 40 mpg, my steering wheel is extremely hard to turn!  My fluid is full and I bled the system with no air. The only time that the steering lightens up is if I’m able to trim the motor up. 

Please don’t suggest putting a cavitation plate on!  LOL

 

As always, Thank You in advance for the help!!!

 

[PRO-V]

Check the manual if you can. I believe it should be mounted so the cavitation plate is about level to no more than 1" below the hull. I believe you need a hydrofoil to solve this.

[ifishwalleye]

So that would help with the porpoising.   What about the hard steering?  Also, that doesn’t take care of the cavitation plate running so low in the water.  

[PRO-V]

It would help bring the bow down which could bring the cavitation plate up. Then you might have to adjust the trim tab on cavitation plate so it steers correctly if still a problem. With bow up high and motor digging deep it will make for harder steering.

[ifishwalleye]

Ok, that makes sense!  Thanks...I will give it a try

[Surface Tension]

We've seen this issue may times before.

A starting point with motor height is cavitation plate even with the bottom of the boat.  From there most adjustments are to raise the motor height.

I'll guess and say you have two batteries in the stern along with the 9.9 kicker.  Get as much weight in the bow as you can.

You may not want the hydrofin but its been the only solution to many of these problems. Your not going to lose any speed but you will get on plane faster and stay on plane at slower speeds.  It should also help out with porpoising. 

 

[ifishwalleye]

I have a 36v and the batteries are located up front under my rod locker. 

[ifishwalleye]

So do you have a recommendation of what hydrofin I should use?  Thanks

[leech~~]

This is some pretty good info. Hopefully you can find out what the issue is without putting a Dork fin on that nice boat!

 

https://www.boats.com/how-to/the-outboard-expert-boost-speed-with-outboard-engine-height-adjustments/

 

 

Edited August 1, 2018 by leech~~

[PRO-V]

Buddy of mine had the same problem and boat layout. Until we put 8 cans of gas and our duffels up front it wouldn't go away. He needed the foil.

[Surface Tension]

 Another option is installing a transom wedge for more negative trim.  Don't know if you can do that with a jack plate installed.  In a perfect world you'd be trimming out when on plane.

  The fin is also an enhancement. As said getting on plane faster but for me the most benefit is staying on plane as slower speeds.  Speeds that otherwise you'd fall off plane, plow water, and bow rise.    The fin will add stability as well.

 

I've recommended trim tabs before but on one wants to go that route.

 

 

[Hoey]

.... or trim tabs.

[ifishwalleye]

I had already talked to my dealer about adding tabs. Unfortunately they will not work with my hull design. 

[ifishwalleye]

First off... Thanks to everyone who responded to my question!

I measured the height of the cavitation plate in reference to the keel. I’m about 1” above keel. 

I bit the bullet and hesitantly installed a “Fin”. I got it from Bobs machine shop , which is located in Florida. It’s a stainless which I thought would be more durable than the plastic. 

 

Well, I hate to admit it but it really helped out with the performance of my Boat!  The bow now rides like it’s supposed to. I lost 2 mph on top end but that’s fine. I am actually able to trim the motor at cruising speed!  

[Hoey]

ifish - that is great news.  nothing like a smiling boat owner/operator.  

[PRO-V]

Good to hear. Glad it worked out for you.

[Surface Tension]

Good to hear the boat behaving better.