boat list to port side while running

KinsmanB

Cadet
Joined
Feb 19, 2005
Messages
12
The boat is an 18 foot center console sportcraft<br />fishmaster.I have tried to adjust the torqe tab<br />on the motor it doesnt seem to help. It seems to have a torque to port side list while planed out.<br />The boat does not list while sitting still.Can<br />anyone out there help me figure it out?
 

Mischief Managed

Lieutenant Commander
Joined
Dec 6, 2005
Messages
1,928
Re: boat list to port side while running

It's from propeller torque. The spinning prop wants to twist the boat counter clockwise. It's why most boats have the helm on the starboard side. Trim tabs will wsort it out nicely.
 

BillP

Captain
Joined
Aug 10, 2002
Messages
3,290
Re: boat list to port side while running

Get ready for the advertisments.<br /> :D :D
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: boat list to port side while running

What MM says is true. This is another reason that I like helm adjustable trim tabs. No add, just experience. My .02
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,778
Re: boat list to port side while running

Funny, I have been wanting to address this.<br /><br />Most props turn CW....that I am aware of. Would think that the engine, hence boat, would want to go in the direction of rotation; hence cw; like if the prop was turning and froze (if it could) it would turn the boat in the same direction; plowing the starboard side.<br /><br />That would make the right (starboard) side low in the water and you'd think they would put the helm on the left to counter it.<br /><br />So now I'm hearing what makes a lot of sense, explaining the boat designers did, in fact, put the helm on the correct side, but from a physics standpoint I don't understand it. Would appreciate a quasi technical answer if anyone has time.<br /><br />Thanks,<br /><br />Mark
 

Mischief Managed

Lieutenant Commander
Joined
Dec 6, 2005
Messages
1,928
Re: boat list to port side while running

Physics 101: For every action, there is an equal and opposite reaction.<br /><br />The engine is turning the prop CW, right? Well it has an equal and opposite effect of trying to turn the rest of the boat CCW. That's it in a nutshell. <br /><br />Another way to look at it is the action of pulling a wheelie on a motorcyle. The engine is rotating the rear wheel "forward" and trying to rotate the rest of the bike "backward". Add enough power and the front of the bike rotates up and backward over the rear wheel. Same concept.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: boat list to port side while running

I can't explain it from scientific standpoint.<br /> But the motor is trying to turn the prop clockwise looking from behind the boat.Thus the boat/motor twists in the opposite direction.<br /> Thus the port side may end up down.This can sometimes be made worse if the boat runs too low in the bow.<br /> I had a 1929 Dodge 25 ft runabout.They placed the helm on the port side like a car.I moved the big 6 volt battery to the starboard side and that big 4,000 lb. boat still would end up low on the port side unless I slid to the middle.It was fine with 2 or more aboard.hope this helps a little.
 

LubeDude

Admiral
Joined
Oct 8, 2003
Messages
6,945
Re: boat list to port side while running

All the above explinations are great, but I bet its just "Bow steer"!<br /><br />You will need to trim your engine out just a bit. If you do not have power trim, raise the engine to the next set of holes on the engine pivot. (not the transom mount), If that helps, go another set of holes untill you get a happy medium.
 

KinsmanB

Cadet
Joined
Feb 19, 2005
Messages
12
Re: boat list to port side while running

Thank You all . I am trying trim tabs. I will repoert results as soon as I can get a day of not so cold weather.
 

b.gagnon

Master Chief Petty Officer
Joined
Apr 28, 2001
Messages
835
Re: boat list to port side while running

Where is the Anti cavitation plate in relation to the bottom of the boat? I had the same problem(real bad) with my boat. I raised the motor on the transom and it got much better, then I got a cupped SS prop and it was gone!
 

Dunaruna

Admiral
Joined
May 2, 2003
Messages
6,027
Re: boat list to port side while running

Is the motor fitted with a doel fin (whale tail/vent plate extension)?
 
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