Strong pull on port

[MORNING LIGHT]

Hi all
Have a Catalina 28 1996 with a 25 XP engine. When motoring , the boat wants constantly to go on port. I have to correct by aiming on starboard by 20-25 degrees to go straight. I have a 13 x 10 with 3 blades prop and owners manual says should be 13 x 7 with 3 blades. ( optional or 13 x 8 with 2 blades std.) Could the pitch difference on prop what causes the boat to react like that ? This prop was on the boat when I bought it 2 yrs ago.

Otherwise, runs great, get 6 knots at 2500 rpm or so but it gets very hard on the arm when motoring for a long time and I can't use my auto pilot. Might be hard on engine too.

Thanks

 

[JohnVTX]

I'm not a prop expert, but my first thought is a bent rudder

 

[LakeOntario270]

My Catalina 270 with a 18hp Westerbeke had a 3 blade 10" pitch with no issues. I would look to the rudder.

 

[MORNING LIGHT]

Thanks but I forgot to say that when sailing, the boat works fine and go straight which tells me it has something to do with the prop.

 

[SFS]

Could it be prop walk? I delivered an Endeavor 37 this summer with a perkins 4-108 in it, and it pulled hard to port ALL the time under power. No autopilot, it was a long 300 miles.

 

[MORNING LIGHT]

Could it be prop walk? I delivered an Endeavor 37 this summer with a perkins 4-108 in it, and it pulled hard to port ALL the time under power. No autopilot, it was a long 300 miles.

I know , but the prop walk act on reverse, my previous boat had a 2 blades prop and never done that. I just need to know what other Catalina 28 owners use as their own prop !

 

[MORNING LIGHT]

I know , but the prop walk act on reverse, my previous boat had a 2 blades prop and never done that. I just need to know what other Catalina 28 owners use as their own prop !

I just can't be the only one with this issue.

 

[Siamese]

I have a 1996 Catalina 28, too. Same engine, but I don't know which prop I have, but have no reason not to believe it's the original.

Like your boat, mine is entirely neutral under sail. Under power, it's similar to your's but perhaps less severe. As rpm and speed increases, the load on the wheel (turning to port) increases. At around 1800 to 2000 rpm, the wheel clutch can keep her in a straight line, but at cruising rpm of 2400 to 2500 rpm, the clutch will not hold reliably. If I take my hands off the wheel (clutch off), the boat will immediately go into a spin. The autopilot on my boat is original, and is non-functioning, but I have't bothered repairing it or replacing it, as I don't know how well it will perform with the tendency to go to port. I have read reports from owners who say their Cat 28 has the pull to port, but are happy with the performance of their (crappy) Raymarine autopilot.

Where mine differs dramatically from your's is that I don't have to compensate at all to go straight. The pull on the wheel is significant, but the rudder is straight.

When I bought the boat (three years ago), in addition to the survey, I did an in water test, followed by a haul out for bottom inspection. On the way to the travel lift, I experienced the pull to port for the first time. While the boat was in the slings, close inspection showed no problems, as confirmed by the service people at a very good sail oriented marina. Searching online turned up information that the Cat 28's pull to port is a characteristic of the vessel and is a function of how the prop interacts with the balanced rudder. I've read that there is/was a replacement rudder available that cures the problem, but I'm not motivated to pursue that option as I have no doubt that if available, it's pricey in the extreme.

With regard to speed under power, at 2500 rpm (my normal cruising rpm), she delivers 6 knots or a little more. At full power, 3100 rpm, pull on the wheel increases, but still, no steering correction is needed to go straight.

Are you certain that you have to make the dramatic steering correction you describe? Is that 20 to 25 degrees of rudder turn, or is that 20 to 25 degrees of wheel rotation?

 

[JohnVTX]

How about the alignment of the prop to the rudder? Have you checked that?

 

[Stu Jackson]

I just can't be the only one with this issue.

You aren't.

Almost all boats do that.

Suggestions to look to the rudder are, IMHO, plain wrong.

Prop walk works in both directions.

Almost ALL Catalinas require you to turn the wheel a few degrees to the right when motoring ahead.

This is normal.

 

[Donnybrook]

My friend had a C28 Mk I, but with the more common M3-20 engine (18hp). He experiment with different props, and found that a 13X8 2 blade prop to be just about right. Did not effect the left pull. If you do have a 25XP, you will probably need more prop pitch. His boat did exactly as you describe. It is normal to have some left hand pull with a right hand prop, but the C28 has a lot more than most. My friend said that the MkII had a different rudder with less area on the leading edge and more on the trailing edge to make it pull less. Don't know if that is true. I made a 23 mile trip on that boat and ended up tying a heavy piece on bungee cord to a short piece of line. I tied the bungee to the top of the wheel and secured it to a cleat on the combing to make the helm neutral. Otherwise, I couldn't let go of the wheel for a second without it slamming to the left stop. Not pretty, but it works.

 

[Siamese]

You aren't.

Almost all boats do that.

Suggestions to look to the rudder are, IMHO, plain wrong.

Prop walk works in both directions.

Almost ALL Catalinas require you to turn the wheel a few degrees to the right when motoring ahead.

This is normal.

Nope. The Cat 28 is in a class by itself for pull to port, and it's not prop walk. Yes, it's normal for a Catalina 28 to have this characteristic under power, but it is by no means typical of all boats or all Catalinas.

 

[MORNING LIGHT]

You aren't.

Almost all boats do that.

Suggestions to look to the rudder are, IMHO, plain wrong.

Prop walk works in both directions.

Almost ALL Catalinas require you to turn the wheel a few degrees to the right when motoring ahead.

This is normal.

Thanks Stu, was waiting for your verdict ! What means IMHO ? Can I damage my auto pilot by using it . When I engange it,
it will work for a few minutes then let go. But I might have a fluxgate compass issue also, not sure.

Thanks anyway

 

[MORNING LIGHT]

I have a 1996 Catalina 28, too. Same engine, but I don't know which prop I have, but have no reason not to believe it's the original.

Like your boat, mine is entirely neutral under sail. Under power, it's similar to your's but perhaps less severe. As rpm and speed increases, the load on the wheel (turning to port) increases. At around 1800 to 2000 rpm, the wheel clutch can keep her in a straight line, but at cruising rpm of 2400 to 2500 rpm, the clutch will not hold reliably. If I take my hands off the wheel (clutch off), the boat will immediately go into a spin. The autopilot on my boat is original, and is non-functioning, but I have't bothered repairing it or replacing it, as I don't know how well it will perform with the tendency to go to port. I have read reports from owners who say their Cat 28 has the pull to port, but are happy with the performance of their (crappy) Raymarine autopilot.

Where mine differs dramatically from your's is that I don't have to compensate at all to go straight. The pull on the wheel is significant, but the rudder is straight.

When I bought the boat (three years ago), in addition to the survey, I did an in water test, followed by a haul out for bottom inspection. On the way to the travel lift, I experienced the pull to port for the first time. While the boat was in the slings, close inspection showed no problems, as confirmed by the service people at a very good sail oriented marina. Searching online turned up information that the Cat 28's pull to port is a characteristic of the vessel and is a function of how the prop interacts with the balanced rudder. I've read that there is/was a replacement rudder available that cures the problem, but I'm not motivated to pursue that option as I have no doubt that if available, it's pricey in the extreme.

With regard to speed under power, at 2500 rpm (my normal cruising rpm), she delivers 6 knots or a little more. At full power, 3100 rpm, pull on the wheel increases, but still, no steering correction is needed to go straight.

Are you certain that you have to make the dramatic steering correction you describe? Is that 20 to 25 degrees of rudder turn, or is that 20 to 25 degrees of wheel rotation?

This is 20 -25 degrees on the wheel and this doesn't happen when sailing. Never tried at full speed since I already get 6.2 knts at 2500-2600 rpm. We go up the st-lawrence river every summer and it takes 2 1/2 days motoring to get there, I get pain in the shoulder holding the wheel that long , that,s why i was looking for a solution !
Thanks

 

[MORNING LIGHT]

How about the alignment of the prop to the rudder? Have you checked that?

Nope, did not do that since the boat does not pull when sailing. If rudder issue, it would pull on port all the time , no ?
Which is not the case.

 

[PineyWoods]

Nope, did not do that since the boat does not pull when sailing. If rudder issue, it would pull on port all the time , no ?
Which is not the case.

Never been on a boat in my 60 years of sailing/motorboating with an engine that didn't have significant torque-steer problems at higher RPM's. Particularly bad with my past Herreshoff Meadowlark 37 with Westerbeke-25 diesel aux. offset about a foot to stbd so that prop was protected by the long skeg. LFH's original design in the 32' version had twin 5HP gas engines, but doubtful they were counter-rotating to cancel the torque.

The autopilot problem was solved by a stout bungee looped around a top wheel spoke and dead-ended on a bimini support, tension adjusted to give a fairly neutral helm at out usual 80% max rev. cruising speed of about 6.5K.
Pete

 

[SFS]

As Stu said, prop walk occurs at all times the boat is in gear. It has more of an effect at higher RPM. For most boats, it is more noticeable in reverse, but it occurs regardless of which direction the prop is turning. Propeller driven aircraft exhibit it all the time.

 

[JohnVTX]

Nope, did not do that since the boat does not pull when sailing. If rudder issue, it would pull on port all the time , no ?
Which is not the case.

Well check it. You asked for suggestions and instead of checking them you tell us that is not the problem without knowing yourself.

 

[Stu Jackson]

What means IMHO ? Can I damage my auto pilot by using it . When I engange it,
it will work for a few minutes then let go. But I might have a fluxgate compass issue also, not sure.

In my humble opinion... there's a website that lists all those things.

Damage an autopilot? Heck, I thought that's what they were for! What autopilot? What do you mean by "then let go?"

 

[JRacer]

This is 20 -25 degrees on the wheel and this doesn't happen when sailing. Never tried at full speed since I already get 6.2 knts at 2500-2600 rpm. We go up the st-lawrence river every summer and it takes 2 1/2 days motoring to get there, I get pain in the shoulder holding the wheel that long , that,s why i was looking for a solution !
Thanks

Small drogue (or line dragging) off the starboard stern cleat?