Mainship 34 Trawler (2005)
Built 2005–2009 by Mainship
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About the Mainship 34 Trawler (2005)
Researched from public sources for this model. Any individual boat may have been modified or repowered — confirm before relying on any figure.
- Built
- 2005–2009
- Builder
- Mainship
- Length
- 38.83 ft
- Beam
- 14.25 ft
- Draft
- 3.33 ft
- Displacement
- 20,000 lb
- Hull / keel
- semi-displacement
- Propulsion
- inboard
- Fuel
- 250 gal
- Water
- 70 gal
- Holding
- 34 gal
- Generator
- factory option
- Bow thruster
- factory option
Tank capacities — where the figures come from
-
Fuel 250 gal
“250 gal / 946 L” — review, canadianboating.ca · “Fuel: 250 gallons in aluminum tank” — search excerpt, trawlerforum.comNo builder document was found; a magazine review and one listing agree with our earlier figure.
-
Water 70 gal
“70 gal / 265 L” — review, canadianboating.ca · “Water: 70 gallons and additional 40 gallon tank” — search excerpt, trawlerforum.comA magazine review agrees with 70 gal; one listing has an extra 40 gal tank on top of the 70, likely an add-on.
-
Holding 34 gal
“34 gal / 129 L” — review, canadianboating.ca · “Holding: 34 gallons” — search excerpt, trawlerforum.comMagazine and one listing agree; no builder document found.
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Water heater unknown
Power & Motoryacht's standard/optional lists do not mention a water heater.
Tanks are often replaced or added on older boats — check the tank labels or a survey for yours.
Thrusters and steering — where this comes from
-
Bow thruster factory option
“Optional Equipment ... SidePower electric bow thruster” — review (2005), powerandmotoryacht.comPower & Motoryacht's 2005 test lists the Side-Power electric bow thruster under optional equipment; the test boat had one.Side-Power — Electric; model and thrust not stated.“SidePower electric bow thruster” — review (2005), powerandmotoryacht.com
-
Stern thruster unknown
Not in the review's standard or optional equipment lists; nothing else found.
-
Steering unknown
The Power & Motoryacht test's equipment lists don't name the steering system, and no other source was found. The same test lists the lower helm as optional.
Thrusters and steering are often replaced — check the units on your boat before ordering parts.
Sources disagree on hp (twin option) — left blank rather than guessed.
Full-keel semi-displacement hull with galley-down single-stateroom layout; lower helm optional. LOA 38.83 ft includes pulpit. Single 240 hp Yanmar cruises about 8 knots (12-13 top); twin 315 hp Yanmars reach 16-18 knots.
Engines fitted
-
Yanmar 240 hp (4-cyl) — 240 hp, diesel, single
standard
HMY's guide gives a single 240 hp Yanmar cruising efficiently at 8 kn (12-13 kn top); Power & Motoryacht says power ran from a single 240 hp up. Base engine per both.Sources: hmy.com · powerandmotoryacht.com
-
Yanmar 240 hp (4-cyl) — 240 hp, diesel, twin
factory option
Canadian Yachting/Canadian Boating tested a 34 Trawler with twin 240 hp Yanmar turbo diesels; P&MY says twin installations to 240 hp were offered.Sources: canadianboating.ca · powerandmotoryacht.com
-
Yanmar 315 hp — 315 hp, diesel, twin
factory option
HMY: twin 315 hp Yanmars reach 16-18 kn top.Sources: hmy.com
-
Yanmar 6LYA-STP — 370 hp, diesel, single
factory option
Power & Motoryacht's January 2005 test boat had a single 370 hp Yanmar 6LYA-STP with a ZF gear.Sources: powerandmotoryacht.com
-
Cummins — diesel, single or twin
factory option
Power & Motoryacht says single and twin installations were offered from both Yanmar and Cummins; the Cummins models and ratings are not named.Sources: powerandmotoryacht.com
Boats of the same model can differ — check which engines yours actually has before ordering parts.
Generator
factory option
“Optional Equipment ... 8-kW Kohler genset” — review (2005), powerandmotoryacht.com
Power & Motoryacht's January 2005 test lists the 8 kW Kohler under optional equipment; the test boat had it.
-
Kohler — 8 kW
factory option
Fuel not stated in the test.“8-kW Kohler genset (optional equipment)” — review (2005), powerandmotoryacht.com · “Powered with a Yanmar 370 hp, and a Kohler 8kw genset” — search excerpt (2007), facebook.com
Generators are often replaced or added — check the unit's own plate before ordering parts.
Known problems for this model
-
Tight engine room access engine
The engine room hatch beneath the flybridge stairs is a tight fit, which makes routine service awkward.hmy.com
Engines & parts
Yanmar 6LY (6LY2, 6LY3, 6LYA-STP) parts: good
Factory optional engine — you entered “Yanmar 6LYA-STP”
Current Yanmar dealer support; cooler service is costly (one owner was quoted about $8,000 for a full cooler service).
Parts sources: Mack Boring & Parts (Yanmar distributor)
Common problems (2)
-
Aftercooler, heat exchanger and oil cooler service cooling
Owners service the aftercooler, coolant heat exchanger and oil cooler about every three years in salt water; neglect shows as green corrosion at seams, corroded O-ring grooves and seized bolts, and can require a new cooler.trawlerforum.com
-
Turbo oil leaks and lag exhaust
Turbos leaking oil into the intake and aftercooler, and slow turbo response with smoke, are recurring 6LYA complaints.downeastboatforum.com · justanswer.com
Maker’s service schedule (21)
| Engine oil & filter change 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 250 hrs or 1 yr | “Change the engine oil after the first 50 hours of operation and then at every 250 hours thereafter.” — manufacturer, nhmr.nl |
| Fuel filters & water separator 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 250 hrs or 1 yr | “When the engine is operated on light diesel oil, replace the fuel filter element every 250 hours or one year of operatio” — manufacturer, nhmr.nl |
| Drain fuel filter and fuel/water separator 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 50 hrs or 1 mo | “Perform the following maintenance every 50 hours or one month of operation, whichever comes first. Drain Fuel Filter and” — manufacturer, nhmr.nl |
| Raw-water pump impeller 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 500 hrs or 2 yrs | “Perform the following maintenance every 500 hours or two years of operation, whichever comes first. Replace Seawater Pum” — manufacturer, nhmr.nl |
| Engine pencil zincs 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 250 hrs or 1 yr | “Perform the following maintenance every 250 hours or one year of operation, whichever comes first. ... Replace the Anode” — manufacturer, nhmr.nl |
| Coolant replacement & freeze-point test 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 250 hrs or 1 yr | “Perform the following maintenance every 250 hours or one year of operation, whichever comes first. ... Replace Engine Co” — manufacturer, nhmr.nl |
| Air filter / intake silencer 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 250 hrs or 1 yr | “Perform the following maintenance every 250 hours or one year of operation, whichever comes first. ... Clean the Air Int” — manufacturer, nhmr.nl |
| Exhaust mixing elbow inspection 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 250 hrs or 1 yr | “Perform the following maintenance every 250 hours or one year of operation, whichever comes first. ... Clean the Exhaust” — manufacturer, nhmr.nl |
| Turbocharger inspection 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 250 hrs or 1 yr | “Perform the following maintenance every 250 hours or one year of operation, whichever comes first. ... Clean the Turboch” — manufacturer, nhmr.nl |
| Valve clearance check / adjust 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 1,000 hrs or 4 yrs | “Perform the following maintenance every 1000 hours or four years of operation, whichever comes first. ... Adjust Intake” — manufacturer, nhmr.nl |
| Injector test / service 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 250 hrs or 1 yr | “Perform the following maintenance every 250 hours or one year of operation, whichever comes first. Check Fuel Injector S” — manufacturer, nhmr.nl |
| Drive belts inspect / replace 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 50 hrs or 1 mo | “Perform the following maintenance every 50 hours or one month of operation, whichever comes first. ... Adjust Alternator” — manufacturer, nhmr.nl |
| Replace flexible engine mounts 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 1,000 hrs or 4 yrs | “Be sure to replace the Yanmar flexible engine mounts every 1000 hours or 4 years, whichever comes first.” — manufacturer, nhmr.nl |
| Heat exchanger & oil cooler cleaning 6LY3-ETP / 6LY3-STP / 6LY3-UTP (6LY3 manual) | 2,000 hrs or 8 yrs | “Perform the following maintenance every 2000 hours or eight years of operation, whichever comes first. Overhaul and Chec” — manufacturer, nhmr.nl |
| Engine oil & filter change 6LYA-STP / 6LY2A-STP (older Yanmar Diesel Engine Co. manual) | 250 hrs or 1 yr | “4.3.4 Inspection Every 250 Hrs.(or 1 yr.) ... Replace the engine lube oil every 250 hours. Replace the lube oil filter,” — manufacturer, s2b4aa72b8b1c7323.jimcontent.com |
| Fuel filters & water separator 6LYA-STP / 6LY2A-STP (older Yanmar Diesel Engine Co. manual) | 250 hrs or 1 yr | “4.3.4 Inspection Every 250 Hrs.(or 1 yr.)” — manufacturer, s2b4aa72b8b1c7323.jimcontent.com |
| Engine pencil zincs 6LYA-STP / 6LY2A-STP (older Yanmar Diesel Engine Co. manual) | 250 hrs or 1 yr | “4.3.4 Inspection Every 250 Hrs.(or 1 yr.)” — manufacturer, s2b4aa72b8b1c7323.jimcontent.com |
| Turbocharger inspection 6LYA-STP / 6LY2A-STP (older Yanmar Diesel Engine Co. manual) | 250 hrs or 1 yr | “4.3.4 Inspection Every 250 Hrs.(or 1 yr.)” — manufacturer, s2b4aa72b8b1c7323.jimcontent.com |
| Drive belts inspect / replace 6LYA-STP / 6LY2A-STP (older Yanmar Diesel Engine Co. manual) | 500 hrs or 2 yrs | “4.3.5 Inspection Every 500 Hrs. (or 2 yrs.) 1 Inspection of AIternator V-Belt Tension” — manufacturer, s2b4aa72b8b1c7323.jimcontent.com |
| Raw-water pump impeller 6LYA-STP / 6LY2A-STP (older Yanmar Diesel Engine Co. manual) | 2,000 hrs | “(Note) The impeller must be replaced periodically (every 2000 hours).” — manufacturer, s2b4aa72b8b1c7323.jimcontent.com |
| Heat exchanger & oil cooler cleaning 6LYA-STP / 6LY2A-STP (older Yanmar Diesel Engine Co. manual) | 2,000 hrs | “4.3.7 Inspection Every 2000 Hrs. (1) Cleaning the Cooling Water System and Inspecting & Adjusting Parts” — manufacturer, s2b4aa72b8b1c7323.jimcontent.com |
Service part numbers (6)
| Oil filter | Yanmar 119593-35100-12 Replaces 119593-35100, 119593-35110 |
“119593-35100-12 Oil Filter” — dealer, oldportmarine.com · “It fits Yanmar 6LY-UTE, 6LY3-ETP, 6LYA-STE, 6LY2A engines. Cross Reference: 11959335110 119593-35110 119593-35100” — dealer, deltadieselparts.com |
| Fuel filter | Yanmar 41650-502330-12 Replaces 41650-502330 |
“41650-502330-12 Fuel Filter” — dealer, oldportmarine.com · “It fits Yanmar 6LY-UTE, 6LY2-STE, 6LY2A-STP, 6LY3-ETP, 6LY3-UTP, 6LYA-STP, 6LYA-STE, 6LY2A engines.” — dealer, deltadieselparts.com |
| Raw-water impeller | Yanmar 119574-42530 | “119574-42530 Impeller Box Kit” — dealer, oldportmarine.com · “compatible with engine models 6LY2-ST, 6LY2-WDT, 6LYA-STE, and 6LY2A-STP” — dealer, shop.marinedieselinc.com |
| Drive belt 6LY, 6LYA, 6LY2(A) |
Yanmar 119593-42280 | “119593-42280 Belt” — dealer, oldportmarine.com · “It fits Yanmar 6LY2A-STP, 6LY2A engines.” — dealer, deltadieselparts.com |
| Air filter | Yanmar 119593-18880 | “119593-18880 Air Element” — dealer, oldportmarine.com · “119593-18880 Air Filter Foam Element for Yanmar 6CX 4CX 6LY 6LP 6HY 6KY 6HYM” — dealer, jlmmarine.com |
| Zinc / anode all 6LY except 6LY3 |
Yanmar 119574-44150 × 4 | “119574-18790 (1) & 119574-44150 (4) Zincs” — dealer, oldportmarine.com · “Oil cooler and heat exchanger zinc anode for Yanmar 4LHA's, 6LP's and all 6LY's (except 6LY3)” — dealer, boatzincs.com |
From the engine maker’s parts lists, or two independent parts dealers. Numbers change with serial number and get superseded — check yours before ordering.
Model sources (4)
hmy.com · powerandmotoryacht.com · canadianboating.ca · powerandmotoryacht.com
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Other Mainship models
- Mainship 34 Diesel Cruiser (34 Trawler, 1978) 1978–1982
- Mainship 34 Pilot 1998–2008
- Mainship 350 / 390 Trawler ?–2005
- Mainship 400 / 414 Trawler 2003–2012
- Mainship 430 Trawler 1999–2006
Researched from public sources. Spotted an error? The sources are listed above — tell us what they got wrong.