Sloppy steering

[Lshulan]

I’m in process of completing purchase of a Mainship 390 that requires constant fast steering correction to maintain a straight course. This is the second MS 390 we’ve sea trialed and both have the same issue. I’m buying the boat regardless but are there any fixes? the first boat‘s autopilot wouldn’t handle the steering corrections. I’m told this is common to 390s, is that the case? Can any modifications to the rudder help? Will an autopilot set up with aggressive correction work (my old Raymarine had three modes, one that it didn’t react immediately to course changes, one more quickly responding and one mode was very aggressive, not letting the boat stray before correcting).

 

[Bacchus]

Fairly common problem on MS. Not familiar w the 350/390 but our 34HT has similar issues. Our Raymarine / Simrad MFD/AP combo seems to handle it well.
Manual steering w the small rudder is challenging. There are rudder mods I've seen reported but I just use AP to hold headings... sometimes make corrections w the AP or switch to standby then back to auto.

 

[Gdavid]

Those boats (350&390) are slow steering due to the rudder so far forward of the submerged swim platform but it should be predictable. Sounds like the system needs to be bleed, got to have a leak somewhere. Some people have added articulating rudders at great cost with good results but there are a lot of these boats out there doing fine without them.

 

[DrissZougari]

My MS390 with a Single Engine does not exhibit the symptom you are referring to. My bridge helm was sloppy when the boat was purchased 3 years ago however, the issue was corrected by bleeding the system.
Did you use the lower or upper helm during your sea trial?
The lower wheel feels different due to its size compared to the upper one!
Good luck,

 

[Lshulan]

Don - thanks for reply, appreciate it. I’m hoping the AP will help. If all goes well with the survey (which I’m absolutely sure it will), we will be new owners soon and then have to figure out getting back to NJ! But I have lots of help for the present owners and I believe you had offered to provide advice as well. Keeping my fingers crossed.

 

[rgano]

Difference MS model here, but pretty tiny rudder which is useless in slow maneuvering. I run on plane most of the time and find the rudder response quite "normal" at those speeds.

 

[Lshulan]

Thanks for all the replies. I’ll have the system checked for needing to be bled once I get home (back to NJ). The issue with the steering was at the upper station, didn’t check it at lower, will do next time out. I had heard of some rudder mods, someone mentioned an articulated rudder which sounds too complicated. What about welding on an extension to make it longer, anyone have any experience with that?

 

[tiz]

Our 2001 single engine 390 does the same thing. Bleeding helped a little. Mostly you learn not to over correct.

Under 2kts I steer with the boat thrusted as the rudder becomes useless.

—Kevin

 

[Lshulan]

Thanks. I will try bleeding it when I get back to the boat. And will try never to go that slow!

 

[Shrew]

The 350/390 is 6 turns lock to lock. Most boats I've owned, particularly planing boats, are 3 turns lock to lock. This takes some getting used to. On 3 turn wheels, quarter turns are all that is needed for micro-adjustments. On a 6 turn wheel, half to whole wheel turns are sometimes needed.

It's not that sloppy, however I do suspect you are either initially understeering, then subsequently over-steering to compensate for the unexpected lack if helm response. Once you get used to it it'll be fine.

Also, I will second or third the suggestion to completely flush and bleed the hydraulic steering. Hydraulic fluid does get old and air can work itself into the system. If the wheel is 'thumping' when you turn it at the upper helm, the hydraulic fluid is low.

 

[Comodave]

One thing to remember is to “meet the helm”. As the boat is turning take the wheel and take some of the turn out because the boat will continue turning for a bit after you straighten the helm up. Each boat is somewhat different so it may take some experimentation to get it right.

 

[Lshulan]

Thanks again to all replies, good info. I previously had a Catamarran and several monohull sailboats so I’m very familiar with how not to oversteer, it just seems like it’s very difficult to steer a straight line at low speed . I would have assumed with the keel, going straight shouldn’t have been an issue. And trying to keep the boat from going off the straight line also shouldn’t have been problematic. But I love the boat and next year gonna get AP which MAY make this less of an issue I hope

 

[bill.kimbell]

Agree, sounds like air in the system.

 

[Cold Duck]

My first experience with my 350 upon purchase was bringing it up the coast from Santa Barbara to SF and into the Delta. In the fog and dark and 30kt winds, bucking 10 ft seas, I could at best hold the 350 +/- 30 degrees, whipping that wheel like the devil. AP was inop at purchase and since is working but I have not had those kind of seas since so no data. I doubt it would have held. I love my 350 but it is the worse handling helm I have ever experienced and I have traveled to Panama and back, numerous trips SF to Mexico, Caribbean et al. The previous owner installed one of those '50s steering wheel knobs on the upper helm (the kind the kids use to have). It really helps when you need to "whip" that wheel around. I agree about leaving wheel in neutral position and docking with thruster. Any attempt to use wheel gets a delayed response which easily goes to an over response especially if wind is up. Once you gain experience with the helm, it will get better. You can bleed system, but don't expect miracles.