Boat walks side to side at idle

[jlash]

I have a 2001 Maxum 1800SR with a 4.3L V6 Mercruiser engine. When in forward gear and going at idle speed the boat will turn slightly to one side and than back to the other. It will continue to do this while going slow. At higher speeds it is fine. I noticed the 4.3 does not have a trim tab. Should it have a trim tab or can anybody tell me why the boat is doing this?

 

[craze1cars]

Re: Boat walks side to side at idle

Believe it or not, this handling characteristic is quite normal for many I/O deep hulled boats...nature of the beast....the hulls are inefficient at low speeds. This "problem" has been covered a good number of times here on this site if you use the search function. Many say that a set of Smart Tabs will lessen or eliminate it, or fussing with the trim on your motor. But many boats continue to do it, and owners just get used to it.<br /><br />Also not having a trim tab is normal for many Alpha 1 Mercruisers, there's just a flat anode plate in its place.

 

[jlash]

Re: Boat walks side to side at idle

Thank you for the information. I did do a search but must of been using the wrong words to search with.

 

[rickdb1boat]

Re: Boat walks side to side at idle

Smart tabs would help alot....<br /><br /><br /> web page

 

[sumcat1]

Re: Boat walks side to side at idle

Smart Tabs eliminated the low speed wander for me as well as improved overall handling.Best money I ever spent on a boat. Not sure but I think if you have power steering there's no need for a trim tab.

 

[WillyBWright]

Re: Boat walks side to side at idle

Motorcyclists are very aware of the lateral sine-wave air currents coming off the back end of a semi. Same thing.

 

[Boatist]

Re: Boat walks side to side at idle

V Hull all wander from side to side at low speed. Just do not over correct and you will find it will usually come right back in a second or two.<br /><br />I belive your out drive should have a trim tab on it. Sure it help for equal steering pressure turning both ways but also helps stop the boat from leaning from the torque of the prop. Many are also made form zink to help protect the prop and other metals.

 

[Jdeagro]

Re: Boat walks side to side at idle

When running at idle speeds the bow is deep in the water and minor current changes will push the bow one way then the other. This is called low speed wander. Although common it is understandable since the single engine is pushing the boat, and is at the opposite end of the boat. If the motor were in the front , pulling the boat, there would be no wander. Yes Smart Tabs will minimize or eliminate the problem, because the tabs are deployed at this speed and create some resistance to "crabing" side to side. Although the Smart Tabs cure the problem it is just one of the side benefits.