14' aluminum leaning heavy to port under power

[masterfabricator]

Hello all. I have a 14' aluminum StarCraft (Holiday 14) that leans heavy to port under power. It has a 1994 Mariner 40 HP ELO 6E9-L 2 stroke which is the maximum rated motor for this boat. It sits perfectly flat at rest and there is no torque on the steering wheel at all (no pull one way or the other) and it's easy to steer even though it is still a cable and pulley style. When its leaning it's still going straight. I'm wondering if anyone here knows how to get this lean under control. I'm not sure it has the right prop, I can't find anything specific to this motor. Can the wrong prop for this size affect the boat torque? Maybe it's trying to move too much water? I spent a lot of time fixing this boat up to take my kids fishing and they were scared out of their mind when I hit the throttle. LOL. They thought we were going to capsize. Any help appreciated.

 

[CV16]

Is the motor centered on the transom? Maybe try loading the weight to the high side.

 

[Seahorse50]

I had this issue with my 15ft tri-hull.
Rated for a max of a 75 hp but with a 90hp on it.
I found my issue to be a weight balance issue. As my wife and 2 kids sat to one side.

However this issue only was noticeable at high throttle.

 

[robert graham]

Check the bottom of hull directly in front of ransom to see if it's "cupped" upwards from aluminum flexing, previous damage....some rather thin aluminum boats can have hulls disfigured fairly easily....

 

[masterfabricator]

Thanks for the replies. I didn't think to check if the motor is perfectly centered as it sits level at rest. I will do that tonight. my two kids and the battery on the port side don't weigh as much as I do and the gas tank was in the center so I don't think it's a weight balance issue. I never would have thought to check the hull for "cupping" I will also check this when I get home and you know what I find. Even at low-ish throttle it starts to lean and by the time I get to half throttle it's just ridiculous how much the starboard raises. I'm hoping the boat itself is just to light for this motor. I will take a picture of the prop when I get home as well and post it.

 

[jbcurt00]

I think the normal term is

hook

for a hull, rather then cupped/cupping. A 4ft to 8ft straight edge should be enough to 'see' the hook. If it is hooked, I'd bet its the starboard side that's hooked, and it's side of the transom is lifting under full throttle pushing the port side down.....

Another possibility is water trapped below deck migrates to port side stern when you are throttled up but can't reach the drain plug to be drained out. That'd be a lot of excess weight...

 

[garbageguy]

Agree w/jbcurt.
Suggest that while you're taking, and posting, pictures of your setup, get some that show any running gear or anything else that might suggest to the good folks here what might be the problem. Get a pic with the straight edge on it. You know what pictures are worth.

 

[masterfabricator]

I will do this tonight and post the pics. thanks again for the replies.

 

[masterfabricator]

Got home too late it was already dark. will post pictures tonight.

 

[masterfabricator]

OK so I have a 48-56232A1 15p prop. It has a little damage but nothing that would cause this type of leaning. I'm posting a picture of each blade. I'm also posting pictures of the hull it's in great shape with no abnormalities. I couldn't find a straight edge but the pictures show it all. Actually it's not letting me upload any pictures.

 

[82rude]

A prop will not do what your describing.You could get some nauticus trim tabs.I have a friend that has the exact same boat with a 40 Yamaha on it so your motor is not the issue or is it?You don't happen to have a long shaft motor on a short shaft boat do you?Or possibly a bent skeg?

 

[Sea Rider]

All boats tend to lean port, prop turns CW and boat CCW, that's why driver sits on starboard side to compensate whether tiller or central console driven. More torque, more than will lean. Sit boaters starboard and check boat attitude. At which lower tail height is water flow passing by at plane provided that OB sits at 90? ?

Happy Boating

 

[82rude]

Somethings not right.My buddies little holiday never did what his is doing .Theres no way a prop should cause that type of lean .Ive sat port side on lots of tillers and never even had that issue?As an aside years ago port side steering was pretty common and ive often wondered what was the REAL reason for starboard steering becoming so prevalent.

 

[masterfabricator]

I'm wondering if 82rude might be right about the shaft. Although I don't think this will cause the lean I am getting more water slashing up than I think is normal. I'm not sure why I can't upload pictures. they are only 1.5meg

 

[Sea Rider]

When you say are you getting more water "slashing up", does that means water around lower leg is splashing out or over transom ?

Happy Boating

 

[masterfabricator]

Yes, kind of straight up. From what I've read now it seems that the cavitation plate is about 5 or more inches below the bottom of the boat....too low......Does anyone know what affects this has?

 

[masterfabricator]

Yes straight up but not a lot. From what I've read now it seems that the cavitation plate is about 5 inches too low......Does anyone know what affects this has?

 

[Sea Rider]

Having back splashes back or over transom means OB sits bit deeep, shim OB with different wooden shim heights till water splashes disappears, probably could be the culprit of boat leaning port side ?

Happy Boating

 

[82rude]

Sea Rider sounds like a long shaft on a short shaft boat don't you think?Cav plate 5 inches below.If that's the case its actually easy to remedy.My friend built an angle iron bracket with maple or oak wood in about a 1/2 hour and it lasted for years.

 

[masterfabricator]

As suspected the cavitation plate is about 4" below the bottom of the boat. I think the boat was originally a short shaft and the transom was changed and raised but not enough. I wonder if redoing the transom which looks pretty easy on this boat will help.