Looking at a 1980 34 mainship

[Jmk2000]

Hey yall, hoping to pick the brains of some mainship trawler folks. I’m looking at a 1980 version with a freshly rebuilt Cummins! My fav motor which makes me very tempted. What I don’t know is what kind of fuel burn I could expect in the boat. Anyone by chance have any input? Thanks in advance.

Josh

 

[Comodave]

Fuel burn will be minimal. If the boat is in good condition with a rebuilt Cummins I would jump on it.

 

[Keysdisease]

You will not find many boats that will sip fuel more miserly than a Mainship 34. Mine did not have a Cummins, so I can't comment accurately. Fuel burn will not be a problem.
Soft decks are what to look for, there will most probably be some spots, flybridge, cockpit, side decks. A few small spots, expected, large areas maybe different.
Like Dave said, if its in good condition and the price is right, these boats are hard to beat for versatility and value.

 

[ranger58sb]

Hey yall, hoping to pick the brains of some mainship trawler folks. I’m looking at a 1980 version with a freshly rebuilt Cummins! My fav motor which makes me very tempted. What I don’t know is what kind of fuel burn I could expect in the boat. Anyone by chance have any input? Thanks in advance.

Josh

Fuel burn is usually not even close to your top-most expenses. Insurance, docking, etc.

And if you run it at displacement speeds, the burn rate with the Cummins B is likely not much different than it would have been with the DD 8.2T we had in our '87 Mk III, or the more common Perkins engines.

We could flog ours up to about 14 kts, but not comfortably; too noisy. We usually ran at around 9 kts (when we were in a "big" hurry) and more like 7 kts for leisure.

-Chris

 

[Gdavid]

I run my 1980 Mainship at 7.5 knots with the T6.354 Perkins (165hp) turning 1700-1800 rpm through a 2-1 transmission. It burns about 2 gallons/hour. I would expect the mechanically injected Cummins to be pretty much the same at this speed as the cylinder displacement is nearly the same 5.8 vs 5.9 and the lower HP versions run very similar fuel injection systems. A higher output version would have the capability to burn significantly more fuel, if you choose to, but of course, that is within your control.

My father had a 200hp T6.354.4 in his first mainship (now he has a 390) and we ran that boat at 2200 rpm much of the time because that is what the previous owner ran it at. The made about 8-9 knots at that and burned about 3-4 gallons an hour, eventually we learned to slow down , more for the sake of noise than fuel savings. My parents ran the boat almost exclusively from the bridge and the noise didn't bother them but I borrowed the boat frequently and my wife and 3 young children were usually in the cabin so the tradeoff for noise and travel time was easy for me.

These boats have a very practical layout, they didn't try to squeeze too much into them so systems are pretty easy to access and work on. Build quality was pretty average for a production boat so the condition of the boat is entirely dependent on the care it has received over its life. Very few were not neglected at some point. If you don't mind doing your own work, keeping up with coring repairs and mechanical maintenance on these boats is about as easy as one can expect on a 40+ year old boat. On the other hand, if you hire everything out, you could spend the value of the boat on keeping it up every single year. The rule of 10% of purchase price in annual maintenance doesn't work out on these lower value boats, it is much higher but you are still operating cheaper than pretty much every boat in the marina.

I love mine, I would like it even more with a Cummins but it is a perpetual project, then again all my dock mates with much newer boats are always working on, or having work done on their boats. Very few leave the slip more often than mine.

Fuel is by far my least annual expense.

 

[Jeff F]

I had a '78 with a Cummins BTA, and generally ran slow - 7 knots or so - to get good FE. Just dug out my log from doing the Loop on that boat a few years ago,

Distance: 5,815 NM
Motor hours: 893
Generator hours: 299
Fuel used: 1,523 gallons; 5,757 l
GPH: 1.7
MPG: 4.4

I'd suggest that as a lower end of possible fuel consumption. It could easily be double or more at a higher cruise speed, but is still pretty good when compared against similar boats. Both the boat and engine are happy at displacement speeds in my experience.

 

[Jmk2000]

I had a '78 with a Cummins BTA, and generally ran slow - 7 knots or so - to get good FE. Just dug out my log from doing the Loop on that boat a few years ago,

Distance: 5,815 NM
Motor hours: 893
Generator hours: 299
Fuel used: 1,523 gallons; 5,757 l
GPH: 1.7
MPG: 4.4

I'd suggest that as a lower end of possible fuel consumption. It could easily be double or more at a higher cruise speed, but is still pretty good when compared against similar boats. Both the boat and engine are happy at displacement speeds in my experience.

Thank you very much for digging out your logs! That’s great info