Boat wont trim out

[thomv39]

Hi all,
New to the boating world. Just bought a 1981 Silvereline I/O and can't seem to get the boat to plane out. Every thing seems to be working the outboard goes up and down but the boat just will not plane out.
Any help would be greatly appreciated.
Thanks THOM

 

[Boatist]

Re: Boat wont trim out

Welcome to the board.
If outdrive outdrive trims in and out and has a enough power to get the boat on plane then you should be able to adjust it.

What exactly is the problem?
Bow to low then adjust drive out.
Bow to high then adjust drive in.

If the bow too low and you can not adjust then do you have a lot of weight up front, or have Trim Tabs, or a hydra foil?

Give us more details as to what the problem is and I am sure someone can help.

 

[thomv39]

Re: Boat wont trim out

thanks for the quick reply
Being so new to this boating thing I am not sure what. I will just explain my day in the water. once we were out in open water and I would start to power up the boat the bow would get higher and higher and not start to plane out. So, I would just keep it at a low speed kind of boring
You said something about adjusting the drive in for bow to high. How do I do that? Or do I really have to throttle up hard to get it to plane out I I'm like I'm missing something simple
Thanks

 

[Don S]

Re: Boat wont trim out

Thom, not sure what engine and outdrive or year system you have, but below is a link to a Mercruiser owners manual. It's a .pdf document a little over 1MB in size, so it will take a while to open. Go to page 32 of the manual and it will explain how the power trim system works. It may be Mercruiser, and you may have an OMC or a Volvo (you didn't say) but the principal is the same in how to use the power trim.

http://www.boatfix.com/merc/Owner/gas/86017101.pdf

 

[thomv39]

Re: Boat wont trim out

Thanks again,
I just took a look at the at the manual. It explains how it, the trim, works up and down, but my problem is with the trim down and in, the boat still does not want to plane out. The bow of the boat just wants to keep creeping higher and higher. I have a 1981 17' silverline with a inline 4 cylinder mercury motor and the outdrive is a mercruiser power trim. One thing I have noticed is that there is no wing plate any where on the outdrive.

 

[Almeja]

Re: Boat wont trim out

Best thing you can do is find an experienced powerboater to go for a ride with you. A few minutes of instruction will be worth it's weight in gold.

If there's something haywire with the tilt/trim or the engine they will figure that out in a few seconds.

 

[thomv39]

Re: Boat wont trim out

Thanks,
Guess that's what I will have to do.
Thom

 

[Don S]

Re: Boat wont trim out

One thing I have noticed is that there is no wing plate any where on the outdrive.

It shouldn't requier any of those things. It should work fine with only the outdrive and the proper sized prop.
I also hope you aren't just going by the gauge for having the drive down or not. If so, forget the gauge is even there and put the drive all the way down till it won't go down any more and try it. If the bow is then plowing, trim the drive up till it feels right and you can get to top rpm and speed. If the speed goes down and the rpm goes up, trim the drive down a little.

 

[thomv39]

Re: Boat wont trim out

Don,
Thanks for the reply. We were looking at the trim guage but also visualy looked at it to make sure the drive was all the way down. No matter what I tried the bow would not come down it would just keep going up in the air. with this in mind is there any thing you can think of that would cause the bow to not want to settle down in the water and plane out.
Thanks to all who have looked at this post and tried to help.
Thom

 

[Silvertip]

Re: Boat wont trim out

Water trapped in the hull. Stern-heavy boat with an engine that is not running properly. To much weight at the back of the boat. Try redistributing whatever loose items you have back there (anchors, etc.). Prop may have way too much pitch. To get on-plane with a small engine you need to go wide open throttle and ease back when on-plane.

 

[Boatist]

Re: Boat wont trim out

Most boats will reach planeing speed in the 18 to 25 MPH range. Rpm range is in the 2000 to 3500 range where it reaches plane.

When you apply power to the boat and the boat starts to pick up speed the boat will push water and create a bow wave. As speed picks up the front or bow will clime this bow wave and the bow will rise up. As speed picks up more you will start to cross over this bow wave but bow will still be high. Finally with enough power and speed you will cross over that bow wave, the stern will lift and the bow come back down on the water. At this point you will be on plane your speed will likely be between 18 an 25 MPH. When you reach planning speed and are no longer climing that bow wave your speed will also increase a lot. At this point you can raise and lower the bow with your trim. If you do not use enough power the bow will always be high and you will not be able to see where you are going.

Every boat is different even in the same model, with different gear and people it will react different. I like to get my 21 foot boat on plane fast. I also have a 3.0L 4 cylinder motor. Until you get on plane your useing a lot of fuel climing that bow wave. So here is how I start.

Make sure everyone is seated and ready to go. Trim the motor in and apply full throttle. I watch the RPMS and when I reach 3500 RPMS I reduce the throttle to keep the RPMS near 3500 rpms. In a few seconds I am on a clean plane and I trim the boat.

If your motor is not supplying enough power you will never get the bow down, but a 4 cylinder Merc on a 17 foot boat would have to be way down on power to not reach a planing speed.

I am an OMC Guy but the Merc guys will correct me if I am wrong. Most Merc I have seen have a single tilt/trim position switch. If the motor is in the trailering postion and you trim down the outdrive will move down quickly until it reaches the trimming range then it will move down or in slowly. Make sure you trimmed it until it is all the way down or trimed in under the boat. At this point should be ready to take off and get on plane. I seen at least one older Merc that had a seperate trailering lever on the back of the throttle control panel.

Make sure you do not have any water in the hull under the motor. Also when you have the outdrive all the way up have someone operate the switch in the down direction and watch the outdrive go down, at a point it should slow down but continue to move down or in.

Good Luck and enjoy the 4Th.