Strange problem with my boat, please HELP!
 

Hey everyone,

I have a 27' Rayson Craft hull that i just put a new engine in and has an XR drive with large standoff box (drive has maybe 2 hours on it). We water tested it yesterday and encountered a strange issue, when we were on plane the boat (even weight distribution) was leaning to the port side, so we tabbed it up to get it level. When we pulled it out of the water, the K planes were off by about 12" ?!? Any ideas as to why they would be off by so much? We checked with a straight edge for hooks and bumps , but nothing significant. Maybe the drive was intstalled improperly?

Also, are 26" long trim tabs too big for a 27' hull?

Thanks for any help/ideas!

do you have a pic?

Unfortunately, i don't have a pic of it. It's over a Pfaff's shop and they are researching why they would be off by so much. If i get a chance to run over there, then i'll take some.

What do you mean "K-Planes were off by 12 inches"?

+1

The port side trim tab was appx 12" lower than the starboard side tab. Usually there is a very small difference in the height of the tabs (for this boat), but to look at it out of the water, even Gordon was confused. I guess they have Dave Rankin coming to look at it and he knows this boat from a previous owner.

Is the boat new to you? Is the new engine more hp than the old one? What is the beam of the boat?

Some single engine long and narrow V hulls will lean. If I run a right hand prop the boat runs fine, but hitting large waves it will drop hard to port. With a left hand prop the boat will lean to port under 3500 rpm, but not bad. Over that rpm she will even out.

If the boat came with large tabs, it may be for a reason.

I'm not sure of the exact width of the beam, but it is a narrow hull. They were discussing the right/left handed prop issue today, but they think that the drive might need to be raised up a bit too. The long tabs are also placed very narrowly (close to the drive). Yes the new engine puts out 800 hp at prop and the previous put out about 650hp, also the new motor is aluminum and weighs about 300 lbs less than the previous one.
I talked to Ron Pace today, who has set up 3 of these exact hulls, and he can't find a reason why these tabs are the size and in the location they are. I'm gonna try and find the original owner/builder and get the theory on what they were trying to accomplish with this set up.

Thanks for your suggestions, you obviously know what you're talkin about...

Long tabs just mean less tab movement is needed for a given amount of effect.

Seems they should be level with one another. That sounds like somebody screwed up.

On my very narrow and deep V Howard 23 Offshore, playing with the tabs was just something that always needed attention. Slow moving tabs are very important, as you'll be making small changes all the time.

The boat will lean into the wind.

Also, the torque from the prop will certainly cause the boat to roll. And the higher the X dimension (the higher the drive), or the more the drive is trimmed up, the more you will see the effect! Power on it will both roll and want to turn one way. Power off, the other.

So its both a steering and tab thing. Narrow boats are fun, but part of that fun is that you've got to stay alert and engaged.

Karmma for bad mouthing Reggie....