boat pulling to port side while underway

[ericcarr2000]

I was wondering If there was anyone out there that could help me out here. While underway the boat pulls to the port, quite strongly too. You have to really hold on to the steering wheel in order to keep her straight. Ive adjusted the little trim tab on the back of the outdrive, dont seem to help out at all. Ive even installed a pair of hydraulic trim tabs, this seems to take care of the listing, but the thing still pulls to the port side. Does anyone out there have any suggestions?

 

[Fed]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

What boat, what motor, how is your weight distribution from side to side & from front to back while at rest in smooth water?

 

[smokeonthewater]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

if you haven't already adjust the tab all the way to port.... often folks adjust them the wrong way

 

[ericcarr2000]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

Ive adjusted the tab to port, and to the starboard side actually to try it. Still to no avail.

if you haven't already adjust the tab all the way to port.... often folks adjust them the wrong way

 

[ericcarr2000]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

It is a 87 Larson dc 190 with a 3.7 mercruiser and alpha one outdrive. It seems to not matter when you try shifting weight around

What boat, what motor, how is your weight distribution from side to side & from front to back while at rest in smooth water?

 

[Port Monster]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

Just a thought but other posts I have read on this issue (besides adjusting the tab) tell you to look at the hull for "hook". A slight bend in the hull at the bottom of the V could cause this problem. Could be from the manufacturer, improper storage on trailer or rack, etc. Another thought is that you are getting some bow steer because your bow is not out of the water enough. Do you see any change when you trim the motor up after you get the boat on plane or is the pull the same??

 

[ericcarr2000]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

The pull seems to be ther same. Ive crawled under her while on the trailer and checked the hull with a chalk line and it seems straight. It feels like its a bit stronger than the typical prop torque... ot sure on what to think of it...

Just a thought but other posts I have read on this issue (besides adjusting the tab) tell you to look at the hull for "hook". A slight bend in the hull at the bottom of the V could cause this problem. Could be from the manufacturer, improper storage on trailer or rack, etc. Another thought is that you are getting some bow steer because your bow is not out of the water enough. Do you see any change when you trim the motor up after you get the boat on plane or is the pull the same??

 

[stackz]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

Put all your weight you can on other side of the boat and trim up a little. If it levels you likely have soaked foam under the floor on port side. When I say weight I mean put several cimder blocks on that side or fat friends while you steer from middle'ish so your weight isnt a factor

 

[stackz]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

To give you an idea...when I pulled my floor...i had 3x each side 3' long sections of soaked foam. Each weighed over 100lb on the scale after pulled

 

[Turn-n-Burn]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

Possible "Power Hook"? Transom weak/rotting?

 

[ericcarr2000]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

Hmmm..So the only way to actually check into this is to pull up the floor and dig in then right. As far as the weight distribution goes, It doesnt seem to matter when it comes to the pulling, it does help out the listing. Looke like Ill be re doing the floor this winter huh....

To give you an idea...when I pulled my floor...i had 3x each side 3' long sections of soaked foam. Each weighed over 100lb on the scale after pulled

 

[Fed]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

Is it very sensitive to trim?
With standard rotation prop trimming out/up will make it pull to the port and in/down will make it pull starboard.
It's caused by the cutting angle of the blade on the up stroke port side compared to the down stroke on the starboard side.
Ideally the propshaft is parallel to the water surface and pushing squarely on the outdrive.

The way I see it is that a boat will have a 'natural' attitude that it will run at and then you should adjust your trim to run parallel to the surface, after that minor trim changes only.
If the natural running attitude isn't right then don't try & fix it with trim, start moving weight front to back or back to front. That's why when I asked about weight distribution I included front/back.
Another thing to consider is the prop itself, if it's too much like a paddlewheel it will try & twist the hull to the port.
Do you have the right prop on it, good condition & pulling good rpm for your motor?

 

[ericcarr2000]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

I have a standard rotation stnless steel prop that is a 19 pitch. It seems that I have the same problems with my 17 pitch prop also.

Is it very sensitive to trim?
With standard rotation prop trimming out/up will make it pull to the port and in/down will make it pull starboard.
It's caused by the cutting angle of the blade on the up stroke port side compared to the down stroke on the starboard side.
Ideally the propshaft is parallel to the water surface and pushing squarely on the outdrive.

The way I see it is that a boat will have a 'natural' attitude that it will run at and then you should adjust your trim to run parallel to the surface, after that minor trim changes only.
If the natural running attitude isn't right then don't try & fix it with trim, start moving weight front to back or back to front. That's why when I asked about weight distribution I included front/back.
Another thing to consider is the prop itself, if it's too much like a paddlewheel it will try & twist the hull to the port.
Do you have the right prop on it, good condition & pulling good rpm for your motor?

 

[sschefer]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

Put a level chalk line on the transom. Put the boat in the water and check to see if the water line is level with the chaulk line. If it is, your foam is probably dry or at least soaked equally. Get in the boat and sit at the helm while some one else checks the line. If it's off by a lot you need to carry balast equal to your weight. In theory, once on plane the boat should be riding level just because of hydrodynamics. Some boats will have a tendancy to lay over because of poor design. Some manufacturers add hook at the stern to overcome this. Sometimes it works, sometimes it doesn't. Those that lay over to port steer to stbd and vice versa.

My 91 Starcraft 1800 FS would lay over and chine walk at 56 but if I poured the coal to it I could push through it and get back up on the stern. During that time it was drive straight time and hold on because the combination of a hull designed for a normal top speed of about 40 and prop torque made steering tough and I had SeaStar Pro hydraulic steering.

So, my question would be, how much hp are you running and is it withing the manufacturers recommendation.

 

[ericcarr2000]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

As far as the HP goes, I am running a 3.7 mercruiser with a rating of 190 HP.

Put a level chalk line on the transom. Put the boat in the water and check to see if the water line is level with the chaulk line. If it is, your foam is probably dry or at least soaked equally. Get in the boat and sit at the helm while some one else checks the line. If it's off by a lot you need to carry balast equal to your weight. In theory, once on plane the boat should be riding level just because of hydrodynamics. Some boats will have a tendancy to lay over because of poor design. Some manufacturers add hook at the stern to overcome this. Sometimes it works, sometimes it doesn't. Those that lay over to port steer to stbd and vice versa.

My 91 Starcraft 1800 FS would lay over and chine walk at 56 but if I poured the coal to it I could push through it and get back up on the stern. During that time it was drive straight time and hold on because the combination of a hull designed for a normal top speed of about 40 and prop torque made steering tough and I had SeaStar Pro hydraulic steering.

So, my question would be, how much hp are you running and is it withing the manufacturers recommendation.

 

[ericcarr2000]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

Also, I found out that this current setup I have is tha same one that camr from the manufacturer. I did repower her a few years ago with the same engine that was in it from the manufacturer.

 

[sschefer]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

Also, I found out that this current setup I have is tha same one that camr from the manufacturer. I did repower her a few years ago with the same engine that was in it from the manufacturer.

I would start with the simple chalk line test then look at the steering for issuses including all moving parts and finally I'd look at the prop unless it too is original and isn't damaged in anyway.

 

[1960 Starflite]

Re: oat pulling to port side while underway

Re: oat pulling to port side while underway

Is it very sensitive to trim?
With standard rotation prop trimming out/up will make it pull to the port and in/down will make it pull starboard.
It's caused by the cutting angle of the blade on the up stroke port side compared to the down stroke on the starboard side.
Ideally the propshaft is parallel to the water surface and pushing squarely on the outdrive.

The way I see it is that a boat will have a 'natural' attitude that it will run at and then you should adjust your trim to run parallel to the surface, after that minor trim changes only.
If the natural running attitude isn't right then don't try & fix it with trim, start moving weight front to back or back to front. That's why when I asked about weight distribution I included front/back.
Another thing to consider is the prop itself, if it's too much like a paddlewheel it will try & twist the hull to the port.
Do you have the right prop on it, good condition & pulling good rpm for your motor?

I thought it was JUST my boat that was doing this. When I leave the channel the trim is all the way down and it will plane quickly. Then as I raise the trim it will steer VERY hard to the right and then straight as I continue to trim up. It just depends on where the trim is set.

19ft. Century, 140hp Mercruiser I/O WOT 4600 rpm. It does wander left to right at no wake speed. Have to chase the darn thing when going slow.