Need Some "Trim" Help

[barthel]

Hey All,

I need a little help understanding trim.

First, the nuts and bolts. I took out our new (to us) boat for the first time today, it's a '98 Stingray 180RS with the Merc 3.0L and an Alpha One Gen II out drive, and what I assume is the stock prop, a 3 blade 21in. It was just me, my wife, our daughter and a cooler.

My "understanding" of trim was to look at the Trim Gauge and basically start in the middle after I set the outdrive down. I realize that trim is not something you "set and forget", I would imagine it needs adjustment due to water conditions, load, etc. We made our way through the no wake zone and hit the channel. The water wasn't choppy and there was little wind. When I gave it some gas the *** end tried to stand up, SERIOUSLY! I gave it more gas trying to get it up on plane, it just seemed to dig in deeper. I did eventually get it up on plane, but it took a lot of gas and by the time the front started to drop it felt like we were standing up on the back.

Through trial and error I figured out that the way the boat ran best was with the trim all the way down (on the gauge). I seem to remember hearing somewhere that running your boat in either full up or full down was not good. If I moved it off of down at all, it would start to porpoise sometimes wildly. When i trimmed it back down, it settled down and rode very well. When cruising, if I started to trim it up (even a little) I would pick up a few miles per hour and the engine would gain some RPM's, but the front end would start bouncing up and down again.

Am I missing something? Am I not doing it right?

 

[90stingray]

Re: Need Some "Trim" Help

You just don't want to start the engine with the drive in the trailer position. While in the water, leaving the dock...start with trim full down. Once on plane begin to trim for best speed if conditions permit. And yes, you will be trimming up and down depending on what you are doing and what your boat is doing. And the bouncing and porposing... well, welcome to the Stingray club. Thats just the name of the game with that hull. I think trim tabs help out but i have not tried. Others that have are sure to chime in.

 

[barthel]

Re: Need Some "Trim" Help

While in the water, leaving the dock...start with trim full down.

Well, that may be part of the problem. I had the trim in the "mid" position (via the trim gauge) in the beginning and for the first few laps around the lake. I was purposely trying NOT to trim full down, but was perplexed because once I did the boat ran like a champ.

 

[Philster]

Re: Need Some "Trim" Help

To get on plane, trim all the way down.

On plane, trim out and RPMs and speed will rise. There are people who trim as far out as possible when running hard and straight. The engine should probably only run to max RPM when trimmed pretty far out. Point is, trim varies with conditions.

You need trim tabs to stop porpoising. Your Stingray boat is notorious for porpoising. Folks here love Smart Tabs. On your boat, tabs are almost a must.

 

[tpenfield]

Re: Need Some "Trim" Help

The trim gauge shows the position of the outdrive . . . so, as you now know, the 'mid' point will have the prop very high and not in a desired operating position. That first time trying to get on plane must have been very exciting . . .

Your trim range will be most of the way down on the gauge and you will find a 'sweet spot' for the boat, with some experience, so that you do not have to fiddle with it constantly.

There are times when you will want to have it most of the way down, like for water sports when you want to get on plane quickly. Then you will bring it back up to the sweet spot.

The outdrive will only go up so far with the trim switch, as there is a protection feature so you don't raise it too far.

 

[barthel]

Re: Need Some "Trim" Help

That first time trying to get on plane must have been very exciting . . .

I don't know that "exciting" quite covers it!

Thanks everyone for your input, it sounds to me like the major issue was that I was doing it wrong based on my understanding of the trim gauge and where it's supposed to be. Once I trimmed it down, I had ZERO issues, but was under the impression (not sure from where) that doing that was a no-no. Obviously I now know differently.

I'm looking into a set of Smart Tabs as we speak.

Thanks again!

 

[barthel]

Re: Need Some "Trim" Help

UPDATE:

I added a set of Smart Tabs to the boat last week and had a chance to run it today. I have to say that I am impressed.

It didn't really seem to holeshoot any better, but it totally cured the porpoising issue and I was able to trim the motor out a bit more than I did last time.

SO, all in all I would say it was a worthwhile investment.