Mainship 430 aft: What's good, what's not?

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Seahawk05

Veteran Member
Joined
Oct 26, 2015
Messages
25
Location
USA
We are planning a purchase in 18 to 24 months.

The 430 two stateroom just seems to fit our checklist perfectly.

Wife loves the liveable space, salon with real furniture and easy access to everything. No ladders, storage good, cockpit to swimdeck, real queen aft master, separate shower stalls, adequate range, add watermaker/can live on hook for a bit.

If we were ready, we would be having a survey done on a fine specimin in Little River SC.

It has the 370 Yanmars with about 2200 hours. Are there any diesels in these boats that are most desirable? Least?

Any problems with the 8kw genset?

Mainship made these for several years.

Anything to seek out or avoid?

Given an independent hull and engine survey with maintenace records, what are other considerations to weigh given year and equipment choices?

We both like the 430 in the two stateroom version....a lot.
 
My 430 has the cummins 8.3 engines and run great. There was a few years with the Yanmars that had bad valves. Some were replaced under warranty and others were cover after major engine failure. There is more information on the Boat Diesel web site.
You can verify the engine serial number to see if these could be an issues. Most issues did show up at about 800 - 1400 hours.
 
The Yanmars with the "bad valves" were either the 315 hp 6LP model or the 440 hp 6LY2 model. The 370 hp 6LY has been a solid engine with minimal vices.

But I would slightly prefer a Cummins for its increased displacement.

David
 
I own the exact boat. I have owned it a little over 2 years. The 370hp Yanmars are great. The 440hp did have some issues. The Kohler gen set is great. No issues with either and plenty of electricity from the 8KW. For the bad, have the swim platform inspected closely, they were not built by Mainship and all have issues with the balsa coring getting wet. Figure about $2000 to $2500 for repair or you can buy a new one for $4500. Very easy boat to work on, most systems are over the counter parts. I have put about 300 hours on mine with no major issues.
 
Thanks Sanderling, David and Vacser. Very much appreciate the first hand knowledge!

Need to digest and ask some further questions.

Gary
 
We searched for the best boat for our situation for some time. It really came down to the Sabreline 43 and the Mainship 430 Aft cabin. They only made 14 or so of the Sabres and they hold a much higher price than the Mainship. We ended up acquiring a 3 cabin 2006 430 aft cabin earlier this year. From my research it seems like the Yanmar 440s were more susceptible to problems than the 370s. We have the 370s and are happy with performance. We get a solid 16 knots at 3,000 rpm with the boat setup slightly under loaded (3,400 rpm WOT). Fuel consumption at that speed is around 0.7nmpg. We've put about 1,700 miles on her already in various conditions and she handles them all very well. We'd chartered a Sabre 42 flybridge the year before and although faster was a very uncomfortable ride in any kind of sea. Engine loading is a big factor for long term engine health. If you can't get to rated speed or higher at WOT at the sea trial it would be cause for concern.
 
We purchased our 2005 MS 430 aft cabin trawler last year from the original owner. It has the Yanmars 370 hp and the genset as you stated. No issues with anything other than routine maintenance, and base lining the maintenance once you buy it. This is our “maintenance year” where we have changed all raw water hoses, fluids and other assessable maintenance issues.

I have a swim platform story, and it relates to the previously mentioned balsa core. We had ours completely rebuilt due to numerous issues at the cost of $6k, but we are now satisfied with it.

This forum has been a Godsend of information and recommendations. We are pleased with the boat, but cruise at 2400-2600 rpm, depending on the tidal current and load the speed changes.

Feel free to reach out to me and we can chat. I love to talk about our Mainship 430, and have received much advice for our fellow forum members.

Jim
 
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We bought our 430 in 2014 with 800 hours on the 370 Yanmars. The 8kw Kohler had 180 hours. We have put 600 hours on the engines since then with only normal maintenance. Ours is the twin stateroom model and we love all the space in the main cabin. The only drawback that we see is all the stairs going to the different levels. But that is good exercise I guess.
 
Thank you all for such valuable insight (including sanderlings excellent detailed post on another thread)

I think that the Yanmar 370's would be excellent for us. The big Cummins sound like the bees knees. I'd rarely if ever run them up, so if they were on an otherwise target boat, then great. The 370's seem a good choice and sufficient.

Thanks for the feedback on the bigger440's. Just a little research after that showed that some of those might have had expensive repairs.

Besides reliability, engine choices and preventive maintenance routines that minimize diesel odors on deck are essential for wedded bliss aboard. Diesel odors in the cabin might result in mutiny.

The swim platform issues on 430 was a total surprise. Thanks for the heads-up and actual costs.

Are the electric throttles (Just two levers control both engines) as desirable as they seem?

In buying used autos sometimes there is a year where the product quality leaps ahead due to an incremental improvement. Is there a watershed year for the 430 where they just solved a problem or used components that are just superior?

We won't buy a boat that has only ladder access to the flybridge or and anything without a step through transom. When you start weeding out the alternatives in this size and require range and water tanks for the Bahamas, there aren't that many choices without getting a much older passagemaker. So, we think that we can live happily with the steps.

If any of you were to trade your boat for something else to meet the mission that you planned st the time you purchased the 430, what would it be? What were your "close second" alternatives?

For the price point, size, etc.....

And are there surveyors that know these boats better than others?

I'm still a ways out and the boats on the market now will likely be sold (or at least I hope so for the owners' sakes). Pulling the facts together in advance helps me, like many others, make better decisions.
 
Seahawk. (I like the name since we're in Seattle) Our boat, built in 2003, has Hynautic throttle and gearshift controls. They are hydraulic (antifreeze coolant) under pressure that use master and slave cylinders. They seem pretty reliable if not allowed to sit for long periods. We usually run at 1600 rpm and 8.5 knots, about 4 gallons per hour, with an occasional run up to clean it out. We don't have any diesel odors except during refueling. We probably have a wet swimstep, but no symptoms yet. Will cross that bridge when we have to. As far as other boats, I would love to have a Krogen, Nordhavn, or Selene, but can't afford them. The Mainship is perfect for us right now. Probably our last boat.
 
Thanks Porman, UNCW, our local state university shares Seattle's iconic brand. I'm a Seahawk of the teal-blooded variety.

Those lower speed fuel burn numbers are very encouraging.

Almost all of the KK 42's in this price range have a ladder to the fly. The few widebodies that don't are rarer than hens teeth. And I have to admit that the relative simplicity of close quarters maneuvering twins vs a single screw will reduce frustration at the dock, especially in places like Charleston where I hear currents can be swift.
 
Speaking of changes in year models. The 1999 to 2002 models all had Aluminium railings and hatch frames. Starting in 2003, All hardware is polished stainless, rails, hatches. I agree with Porman, I am always looking to go into a bigger boat, but for all the features you get with the 43, Wide beam, 14/15 knot cruise. Full Queen aft master, 2 large showers, plenty of flybridge seating, it is impossible to find in just 43ft and this price range. We have had ours in the Bahamas for 18 months, the 250 gallons of water comes in nice also.
 
Yes, the 250 gallons of water is nice. We spent 3 months in the Broughton Islands, at the North end of Vancouver Island, last summer. We could go for 3 weeks before needing water. This winter I had the choice of spending money on a watermaker or diesel hydronic heat. I went with heat. We use our boat all year and warm is nice.
 
As mentioned above, we found only the Mainship 430 Aft Cabin and Sabreline 43 would meet our needs: flybridge, no ladders, 3 cabins with 2 separate bunks in 3rd cabin for our kids when guests were on board, 16 knot cruise when needed so we can reach anywhere on the northern Chesapeake on weekend trips. We love the layout and the different spaces on board to hang out, and we use all of them. We've had 6 on board for a week in Florida and been very comfortable. Usually it's us, the kids and a dog. Can't understand why no-one makes a similar boat today.
 
The 2 stateroom 430 in Little River, SC is still on the market and I wish we were ready. Patience must be a virtue because it doesn't feel so wonderful today.... :)

The right boat at the right time at the right price will come along. :)
 
Hi There,

Looking for more information from 430 Aft Cabin Trawler owners...

I have twin Yanmars, 370hp engines, turning 24"x24" propellers. When I bought the boat it came with an extra set of 26"x24 props. I'm planning to put the 26"x24" props on this season to see the difference - assuming I can escape NY and visit my boat in CT.

Does anyone have any feedback on what performance differences I can expect? or other thoughts?

Thanks,

Jim
 
With the current props what is the max RPM that you get and what does Yanmar say the max should be?
 
I only had the engines at WOT once during the on the water survey. That was at 3450 if I remember correctly. We typically cruise at between 2200-2400rpm and I have learned that I should be cruising more towards 80% of WOT at 2760.

I am trying the 26"x24" props to see the difference. I have to haul the boat mid season for some fiberglass repairs and if I don't like the performance, I can always change back to the 24"x24" props.

Thanks for any advice.

Jim
 
Hi jimL. Same boat, same engines. During the survey it was noted that the max rpm possible was 3000. The props were 25X26. I had the props re-pitched to 25X24 and now the engines reach a max rpm of 3300.
 
Hi JimL. I also have same boat and engines. The max continuous running speed recommended by Yanmar is 3100 rpm. The 1 hour running speed is 3300 rpm. I like to have my WOT be around 3400 rpm at the start of the season with fresh bottom paint and average displacement. You want the WOT to ALWAYS be above 3300 rpm otherwise you are overloading the engine at any speed. There are differing opinions out there about what is the best speed to cruise at. Some say you should run diesels at their continuous rated speed. Others say stay well below it. But if you do run consistently below, then you'll want to run hot for an hour every now and again to get them to temperature and burn off coke build up. If you were at 3450 rpm indicated on the seatrial, I'm not sure I'd do anything to increase the load on the props. If you do, then you must check to see if you can still reach 3300 rpm WOT. Also, you need to check the accuracy of your tachs. I did with mine and found that they were within 50 rpm at most speeds which is great. There are many reports out there though of tachs reading high and being off by over 100 rpm. You just have to ensure that your engine is actually reaching 3300 rpm WOT minimum.
 
Thanks everyone for your contributions.

I went back and reviewed my survey from 5 years ago. This is the verbiage from the survey:

Performance Results:
1200 RPM - 8 MPH, 2700 RPM - 14 MPH, WOT 3600 RPM - 24 MPH.

The survey was on an inland lake with no wind or current. I was mistaken at the max RPM of 3450. To date, I have not pushed the engines much beyond 2900 RPM and I was in a passing situation on a tidal river and was not paying attention to the speed (Was trying to pass a barge)

My question resolves around experimenting with changing the props that were on for the sea trail above (which were 24"x24") which are on now, to the "spare props" that I intend to mount that are 26"x24".

What changes can I expect with the 26"x24" props with respect to WOT, cruising speed, and fuel efficiency.

I realize this is an open question, but I do appreciate your thoughts and recommendations.

Jim L
 
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Your boat seems to be quite quick! My numbers are
7.5 mph @ 1200 rpm
18 mph @ 3000 rpm
If you change to a larger diameter but same pitch then you will see a lower WOT rpms but higher speeds at the same rpms compared to what you have now. Given that your WOT is 3600 you have plenty of room to load up the prop and get better performance. Just make sure your WOT doesn’t drop below 3400. It was also be worth checking your actual engine RPM using a tachometer to calibrate your tachs so you know they are telling the truth.
 
Thank you, this information is what I was looking for.

Jim
 
TJ, Have you recorded your WOT RPM with the props you currently have?

Jim
 
Mainship 430 refrigerator

We currently have 2 - refrigerator/freezer units stacked on top of each other. Each unit is approximately 2.5 cu. ft. Thinking of replacing with 1 - 8 to 9 cu. ft. refrigerator/freezer unit. Does anyone have experience and advice with this project? Thanks in advance.
 
I had a 2005 MS 430PT with twin 440 Yanmars. I put 3,000 hours on them in 6 years and never had a problem. I sold that boat in 2019 and it is still going strong. The issue with the burned valves was on a Hinkley jet drive boat and was determined to be a mismatch. Wrong engine for the jet drives. I now own a 20077 Mainship Pilot with twin 440 Yanmars and have not had any problems. Do the research to find out what the issue was before you condemn the 440's. They are excellent engines and will give years of trouble service.
 
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