Lean to port---Prop maybe?

[pra100]

Guys I am trying to track this down.Can a prop cause my boat to lean toward the port when under way?I have a 19' mariaha with 4.3 cobra,4 bbl.I put a new Michigan Wheel 19" 4.5 3 blade aluminum prop on 2 years ago after I broke the prop that was on it.The original prop was of same size but was a OMC brand.Didn't seem like it leaned with the old prop,ofcource that was 2 years ago,so hard for a older fellow to remember.Now with the Michigan Wheel prop when I get up on plane and all the way up to wot it seems to lean to the port side.It runs straight,no pulling just leans.Now this is with different loads in it,even with just myself.It does have a fin on drive.I tried taking the fin off and it just made it take longer getting on plane.The boat runs 4800 rpms at wot and by my gps 52.4 mph on a good day with light load.Thought all this was just me thanking that but my wife says it leans to her.Any thoughts on this?

 

[Texasmark]

Re: Lean to port---Prop maybe?

I would go to WOT and get the boat up to speed and chop the throttle. The boat should yaw (change direction of travel) a little from prop torque, but if it is causing the list, the list should correct/attempt to correct when you chop the throttle. Then you know.

And yes, I have read about props causing listing. One reason for the helm being on the starboard side it to counter list caused by the (most common) rt hand rotating props.

My 2c,

Mark

 

[pra100]

Re: Lean to port---Prop maybe?

Yes I have noticed if I drop the throttle real fast it levels off so i guess you are right and my thoughts on it are right.Wonder why a prop would cause that?I have even had weight shifted to starboard side to corrected with no help.

 

[Texasmark]

Re: Lean to port---Prop maybe?

Well, if you think about it, what is there to offset the turning torque of the prop? The skeg of the engine and the hull of the boat.

On a bass boat at 65 mph, there isn't much of either in the water. Personally, I don't know how they do it.....stay level at those speeds. But I've never been to 65. 55 was my highest number.

Mark

 

[Crownie2]

Re: Lean to port---Prop maybe?

Are you trimming the boat correctly? This may fix it.

Also do you have a little trim tab on the back of the anti ventilation plate? Sometimes adjusting this can help. Try adjusting it to port as seen from the rear.

Bob

 

[pra100]

Re: Lean to port---Prop maybe?

Well I thought about the little trim tab.But I was thinking wouldn't that just make it want to turn,or pull to that side by adjusting the trim tab/

 

[Crownie2]

Re: Lean to port---Prop maybe?

If it pulls or leans to the right, it might counteract the left lean to some degree. I think it's worth a try.

I also know some boats just lean left and it is often a weight imbalance issue - but you said you addressed that issue.

Bob

 

[walleyehed]

Re: Lean to port---Prop maybe?

It would be most obvious to me, to be looking for a hull problem....especially after moving all gear starboard and it still does it.
Could be a twisted whale-tail too, but I doubt the tab is causing the list.

 

[pra100]

Re: Lean to port---Prop maybe?

Ok I got my old prop out that is the same size with a few little dings in it.I put this prop on.Now some one explain this to me.Boat ran same speed by gps,same rpms,4800 at wot,but did not lean to port,was just as level as could be.This is blowing my mind.By the way the secound prop which I get the lean with is a Michagan Wheel which I ordered new as a direct replacement for my boat.

 

[walleyehed]

Re: Lean to port---Prop maybe?

Rake could be different, where the cupping is, etc...
What "IS" the original prop model and manufacture?

 

[pra100]

Re: Lean to port---Prop maybe?

The original prop has this on it "14 1/2 x19. and number 39201.That is all that is on it which is located on the hub .The new one that I bought is Michigan ,011008,14.5x19.

 

[walleyehed]

Re: Lean to port---Prop maybe?

That would be a 391201..OMC prop and a good one..
The 011008 is the MWC and should be simular, but I don't understand the list...
If it were me, and you liked the 391201 OMC, I think you would really like a 14-1/4X19 Stiletto...
I would still look the hull over as good as you can...every prop leaves more or possibly less wetted surface in the water at given RPM settings/speed, while on plane.