Port to starboard

[Nason]

If a motor is off center by 1/4 inch on the transom, would this make a boat want to bounce port to starboard at mid range speed or could it be from motor being to high on transom?
At full throttle it plains of correctly, just when you come off the throttle to mid range is when the port to starborad bouncing occurs.
Thanks for any info in advance

[Gene East]

This being primarially a racing site, we tend to say left and right most of the time. I stopped saying port and starboard when I got out of the Navy 50 years ago.

My opinion would be more likely height than offset. Do you have any cavitation problems when this occurs?

If you gave us more info such as size of boat, HP of motor, speed etc. perhaps someone else will join in with some ideas.

How severe is the bouncing? Does it cause handling problems or is it just a nusiance issue?

[zul8tr]

I assume by your explaination that your boat shifts left to right. Does it continue this cycle at the noted speed?
Does the boat have a keel? If yes describe the configuration or take a pic.
Being off center 1/4" does not seem like a significant amount and I suspect something else is causing the problem.
Does the engine have an adjustable trim tab below the cavitation plate? If yes where is it set? A pic would help.
You might have some issues with the hull shape that come into play at a certain speed.
Where do you have the engine angle set? Kicked out, in or level relative to the bottom planing surface?

[Nason]

Boat is 15 x 48 v weldbilt and the motor is a 40 hp merc with a little work done to it. Boat jumps up with no problem with a 10-3/8 x 18p chopper, also with a 11 x 15p fishing prop but i run out of prop with the 11x15p also ran a ron hill semi cleaver 11-1/4 x 19p.same results on all props. Speed i would say between 15-25 mph. At full throttle no problems. No problems handling the boat while its bouncing left to right . I just got this boat and made 4 runs with it then had to go offshore. Going in tuesday and wanted some ideas to try when i get home. I think its more of a height problem. I will be adding a homemade extended cavitation plate a little wider than the original.
ALSO THE BOUNCE IS REALLY COMING FROM THE LEFT SIDE, I TRIED SHIFTING THE BATTERY TO OPPOSITE SIDE FROM WHERE I SIT(TILLER HANDLE) BUT IT STILL DID THE SAME THING.

[chris3298]

is it kinda like a bounce and skip bounce and a skip across the water? Mine has done this some as I'm getting up on a plane but wide open throttle it's fine, I tried calling you but I guess cell phones don't work offshore haha

[Nason]

Thats what its doing but its a steady bounce on the left side. I'll call you tuesday i keep the cell phone off out here in the gulf