J/Boats J/105
Built 1992–? by Tillotson-Pearson (TPI)
About the J/Boats J/105
Researched from public sources for this model. Any individual boat may have been modified or repowered — confirm before relying on any figure.
- Built
- 1992–?
- Builder
- Tillotson-Pearson (TPI)
- Designer
- Rod Johnstone
- Length
- 34.5 ft
- Waterline
- 29.5 ft
- Beam
- 11 ft
- Draft
- 6.5 ft
- Displacement
- 7,750 lb
- Ballast
- 3,400 lb
- Hull
- fiberglass-cored
- Hull / keel
- fin keel
- Rig
- sloop
- Propulsion
- inboard
- Fuel
- 12 gal
- Water
- 5 gal
- Holding
- 12 gal
- Bow thruster
- not fitted
- Stern thruster
- not fitted
- Steering
- tiller · Edson
Tank capacities — where the figures come from
-
Fuel 12 gal
“12-gallon alloy fuel tank with baffles and inspection/clean out port” — builder (current-spec (Yanmar 3YM20) boats), cdn.yachtbroker.org · “12-gallon alloy fuel tank with baffles” — spec database (current production), revandroam.comJ/Boats' standard specification sheet, in a copy hosted by a broker, gives 12 gal. It describes recent builds, so early-1990s hulls aren't separately confirmed; Sailing Magazine says 10 and a J/Boats blog 13.
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Water 5 gal
“fresh water foot pump and 5 gallon portable water tank” — builder (current-spec boats), cdn.yachtbroker.orgThe standard boat has only a 5 gal portable tank. J/Boats' optional Systems Group Package adds a fixed fresh-water tank under the starboard berth with a deck fill, size not stated, so some boats carry more.
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Holding 12 gal
“marine head with 12 gal polyethylene holding tank or "Y" valve for direct offshore discharge” — builder (current-spec boats), cdn.yachtbroker.org
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Water heater unknown
“Galley unit with polished stainless galley sink with fresh water foot pump and 5 gallon portable water tank (standard);” — builder, cdn.yachtbroker.orgJ Boats' J/105 specification (a later edition, copy hosted by a broker) gives a foot-pumped galley with a 5 gal portable tank; its options list adds a fixed tank and vanity foot pump but no pressure water or 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 not fitted
“Options ● Two Tone Deck ... ● Custom Wheel Package ... ● Thurston Dodger with Side Curtains. (full option list; no thrus” — builder, cdn.yachtbroker.orgThe J/Boats J/105 specification sheet (a builder document, posted by a broker) gives the standard equipment and full factory option list, with no thruster in either. It is undated and comes from later production.
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Stern thruster not fitted
“Options ● Two Tone Deck ... ● Custom Wheel Package ... ● Thurston Dodger with Side Curtains. (full option list; no thrus” — builder, cdn.yachtbroker.orgThe same builder standard and option list used for the bow thruster offers none.
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Steering tiller · Edson
“Composite tiller with adjustable hiking handle.” — builder, cdn.yachtbroker.org · “Custom Wheel Package: Edson Racing Series 48" Black Aluminum Wheel ... Custom GRP Molded Pedestal with SS Guard; Aluminu” — builder, cdn.yachtbroker.orgA tiller was standard; the factory wheel package was an Edson 48 in. wheel on a molded pedestal with an emergency tiller (the steering mechanism isn't stated). The Edson brand applies to the wheel option only.
Thrusters and steering are often replaced — check the units on your boat before ordering parts.
Straight shaft drive, not a saildrive (Sailing Magazine); class rules call for a Martec folding prop. Introduced 1992 (Practical Sailor, Sailing Magazine); sailboatdata lists 1995 as first built. Over 500 built by 2002. SCRIMP resin-infused hull and deck with Baltek balsa core and vinylester outer layer; hull-deck joint bonded with Plexus; lead bulb on a fiberglass keel stub; hull stringers molded in from hull 156. Engine hp differs: sailboatdata and PS say 20 hp Yanmar 2GM20F, Sailing Magazine says most have 18 hp Yanmars (French-built boats Volvo 2020). Fuel 12 gal (sailboatdata) vs 10 gal (Sailing Magazine); standard 5 gal portable water tank, 20 gal tank optional.
Engines fitted
-
Yanmar 2GM20F — 20 hp, diesel, single
standard
sailboatdata lists a Yanmar 2GM20F diesel, 20 hp, as original equipment (builder listed as J Boats/Tillotson Pearson; introduced early 1990s). The existing data gives the same engine at 18 hp.Sources: sailboatdata.com
Generator
Not in the specification's standard or options lists.
Known problems for this model
-
Rudder bearings corrode and bind steering
The aluminum upper and lower rudder bearings corrode, especially with copper bottom paint or lost zincs, and typically last only a few years before binding.practical-sailor.com · sailingmagazine.net
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Chainplate bulkhead leaks rigging
Some boats have had leaks and bulkhead damage where the chainplates attach; check for delamination of the bulkhead.sailingmagazine.net
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Cracked forward hatch frame deck
On early boats the stainless foredeck hatch could open past 180 degrees and crack its welded frame; a stop bumper and weld kit were offered.practical-sailor.com · sailingmagazine.net
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Leaks at the retractable sprit tube deck
Water can enter the forward cabin through the sprit tube seal; inspect it.practical-sailor.com · sailingmagazine.net
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Rotting plywood floorboards interior
The shallow bilge wets the original plywood floorboards, whose unsealed end grain rotted or delaminated; later boats got a synthetic sole.practical-sailor.com
2 more
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Engine movement makes dripless seals leak running gear
The Yanmar moves a lot on its soft mounts, which has caused dripless shaft seals to leak on some boats.practical-sailor.com
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Clogged fuel line power loss fuel
The class association issued a service note after several boats lost power or air-locked in heavy seas from a clogged fuel line.archive.j105.org
Engines & parts
Yanmar 2GM / 2GM20F parts: good
Factory standard engine — you entered “Yanmar 2GM20F”
Well supported by Yanmar dealers and aftermarket; stainless mixing elbows that replace the OEM part numbers are widely sold.
Parts sources: Mack Boring & Parts (Yanmar distributor), HDI Marine (stainless exhaust elbows), Parts4Engines
Common problems (2)
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Nearly blocked mixing elbow exhaust
Owners find the exhaust port of the mixing elbow almost completely blocked while the engine still runs; a failed U-elbow has also let water into a cylinder and cracked a piston.sailnet.com · practical-sailor.com
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Noise and vibration from soft mounts engine
Worn soft engine mounts are a common cause of the vibration owners complain about; better aftermarket mounts are available.practical-sailor.com
Maker’s service schedule (2)
| Fuel filters & water separator | 250 hrs | “The normal replacement interval for the element is 250 hours ... Filter cleaning First time 50 hours Filter element repl” — manufacturer, c320.org |
| Air filter / intake silencer | 250 hrs | “Washing period Every 250 hours” — manufacturer, c320.org |
Service part numbers (10)
| Oil filter | Yanmar 119305-35170 Replaces 119305-35151, 119660-35150 |
“2GM20F Basic Service Kit ... 119305-35170 FILTER ASSY, D68XL65” — dealer, oldportmarine.com · “Suitable for: ... Yanmar 2GM, Yanmar 2GMF, Yanmar 2GM20, Yanmar 2GM20-YEU, Yanmar 2GM20F” — dealer, marinepartsystem.com |
| Fuel filter | Yanmar 104500-55710 | “Fuel Filter Element 1 104500-55710 / Fuel Filter O-Ring 1 24341-000440” — dealer, ellebogen.com · “2GM20F Basic Service Kit ... 104500-55710 ELEMENT, FUEL FILTER” — dealer, oldportmarine.com |
| Raw-water impeller Japan-built 2GM / 2GM20(F) (serial not starting with E) |
Yanmar 124223-42092 | “Impeller 1 124223-42092 / Impeller Gasket 1 124223-42110” — dealer, ellebogen.com · “2GM20F Basic Service Kit ... 124223-42092 IMPELLER, PUMP” — dealer, oldportmarine.com |
| Raw-water impeller European-built GM-YEU (serial starting with E) |
Yanmar 128990-42570 Replaces 128990-42200 |
“Impeller & O-ring Kit-128990-42570 For the GM series engines with serial numbers beginning with an E” — dealer, oldportmarine.com · “(Supersedes part number: 128990-42200) ... GM-YEU series engines:(Serial number begins with an E)2GM20-YEU” — dealer, palmerpower.com |
| Drive belt | Yanmar 25132-003700 | “Alternator Belt 1 25132-003700” — dealer, ellebogen.com · “2GM20F Basic Service Kit ... 25132-003700 V-BELT, A37” — dealer, oldportmarine.com |
| Drive belt | Yanmar 104511-78780 | “S/W Pump Belt 1 104511-78780” — dealer, ellebogen.com · “2GM20F Basic Service Kit ... 104511-78780 V-BELT, M/19” — dealer, oldportmarine.com |
| Air filter | Yanmar 128270-12540 | “Air Filter Element 1 128270-12540” — dealer, ellebogen.com · “2GM20F Basic Service Kit ... 128270-12540 ELEMENT, AIR CLEANER” — dealer, oldportmarine.com |
| Zinc / anode raw-water 2GM / 2GM20; also sold for the F (heat-exchanger) versions |
Yanmar 27210-200300 | “27210-200300 Yanmar Engine Zinc Anode For 2GM(D), 3GM(D), 2GM20, 3GM30” — dealer, zincsforboats.com · “It fits Yanmar 2GM, 2GM20F, 2GM15, 2GM20, 3GM30F, 3GMF, 3HMF, 3GM30H engines.” — dealer, deltadieselparts.com |
| Thermostat 2GM20F / 2GMF (fresh-water cooled) |
Yanmar 121750-49800 | “Thermostat 1 121750-49800 / Thermostat Gasket 1 129350-49541” — dealer, ellebogen.com · “Thermostat for Yanmar 2GMF, 3GMF, 3HMF, 2GM20F, 3GM30F, 3HM35F / REC121750-49800” — dealer, marineparts.eu |
| Thermostat 2GM / 2GM20 (raw-water cooled) |
Yanmar 105582-49200 | “Replaces Yanmar Marine 105582-49200 ... 1GM, 2GM, 3GM, 1GM10, 2GM20, 3GM30” — dealer, repowermarine.com · “1GM10, 2GM20 & 3GM30 Thermostat to fit raw water cooled engine versions ... equivalent to 105582-49200” — dealer, parts4engines.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.
Steering
Edson — Pedestal chain-and-wire steering parts: good
Edson (New Bedford, MA) still sells service parts: chain-and-wire kits, sprockets, idlers, pull-pull conduit steering and internal pedestal parts, and keeps steering data sheets by boat model, many decades old.
Parts sources: Edson Marine (service parts)
Common problems (3)
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Old or slack steering wire steering
Edson advises replacing steering wire about every five years, checking tension with the wheel locked, and inspecting under load annually; owners often find decades-old stiff wire.usna.edu · youtube.com
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Lubrication and fastener checks steering
Chain, wire, sheaves and pedestal bearings need regular oiling or greasing, and clevis/cotter pins and bolts should be checked monthly to avoid failures.usna.edu
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Replacing engine control cables in the pedestal steering
Swapping throttle/shift cables inside an Edson pedestal is a common owner job requiring removal of the wheel shaft sprocket pin.forums.sailboatowners.com
Edson — Traditional geared steerers (worm / rack-and-pinion) parts: good
Edson says its traditional wheels and geared steerers are still available, now built with modern materials; rack-and-pinion steerers are offered for transom-hung and inboard rudders.
Parts sources: Edson Marine (traditional steerers)
Model sources (8)
sailboatdata.com · practical-sailor.com · sailingmagazine.net · archive.j105.org · jboats.com · jboats.com · cdn.yachtbroker.org · revandroam.com
Other J/Boats models
- J/Boats J/24 1977–?
- J/Boats J/30 1979–1986
- J/Boats J/35 1983–1992
Researched from public sources. Spotted an error? The sources are listed above — tell us what they got wrong.