The JH-CR series is the current, common rail generation of Yanmar's long-running JH line — for decades the default auxiliary diesel in cruising yachts worldwide. The range we supply spans five models: the compact 3-cylinder, 1.64-litre 3JH40 (40 MHP), and four 4-cylinder models sharing a 2.19-litre block — the naturally aspirated 4JH45 and 4JH57, the turbocharged 4JH80, and the turbocharged and intercooled 4JH110. Every model uses a Bosch common rail direct injection system in place of the mechanical injection of earlier JH generations.
Common rail is what defines the family's character: noticeably quieter running, less vibration, a virtually smoke-free exhaust and strong fuel economy, while meeting current recreational emissions standards. Yanmar launched the 3JH40 as the world's smallest common rail inboard marine diesel, and the whole series keeps the compact footprint and conservative, long-service engineering that made the JH name — which is why it remains the benchmark repower choice for sailing yachts.
The JH-CR Series range
As a rough guide: the 3JH40 suits smaller monohulls where space and weight are tight; the 4JH45 and 4JH57 are the volume choices for typical cruising yachts, with the 57 the safer pick for heavier hulls or owners who motor a lot; the turbocharged 4JH80 steps up for heavy monohulls and per-hull power in cruising catamarans; and the 4JH110 tops the range for heavier displacement boats that need real reserve. Because the four-cylinder models share the same 2.19-litre block, physical size changes far less than power does — so sizing comes down to displacement, hull type, gearbox ratio and propeller rather than length alone, and we confirm the match at sea-trial commissioning.
3JH40
40 MHP3-cylinder · 1.64L · Bosch common rail direct injection
View engine
4JH45
45 MHP4-cylinder · 2.19L · Bosch common rail direct injection
View engine
4JH57
57 MHP4-cylinder · 2.19L · Bosch common rail direct injection
View engine
4JH80
80 MHP4-cylinder · 2.19L · Bosch common rail direct injection with turbocharger
View engine
4JH110
110 MHP4-cylinder · 2.19L · Bosch common rail direct injection with turbocharger and intercooler
View engineDrive options
Shaft drive
All five models pair with a conventional shaft installation through a Yanmar marine gearbox — the usual fit for displacement motor boats, workboats and shaft-drive sailing yachts.
SD60 saildrive
Yanmar's SD60 saildrive bolts directly to the 3JH40, 4JH45, 4JH57 and 4JH80, giving a compact, low-vibration package that's the natural choice for sailing yachts and catamarans already set up for saildrive.
SD15 saildrive
For the top of the range, Yanmar's heavier-duty SD15 saildrive pairs with the 4JH80 and 4JH110, bringing saildrive installation to larger sailing monohulls and cruising catamarans that need more power than the SD60 package covers.
Boats this family suits
Pricing, repower advice or a spec for your boat
Tell us your vessel and how you use it — we'll recommend the right model and drive, with dealer pricing.
Why buy your JH-CR Series from Mariner
Common rail refinement
Bosch common rail injection gives the JH-CR range quiet, low-vibration running with a virtually smoke- and odour-free exhaust — a step change over the mechanically injected engines most owners are replacing, without giving up the JH line's reputation for simple, durable engineering.
The sailboat repower standard
The JH family is the engine most older yachts were built around, so the JH-CR's compact dimensions make it a natural changeover for tired Yanmar GM- and JH-era engines and other brands' auxiliaries. We manage the whole repower — engine beds, shaft or saildrive fit-up, exhaust, panel and controls — and commission with a sea trial on Port Phillip Bay.
Authorised dealer backing
Mariner Engineering is an authorised Yanmar dealer in Spotswood, Melbourne, with factory-trained technicians, Yanmar diagnostic tooling and genuine parts — so the engine we sell you is also one we can properly service for its whole life.
Yanmar JH-CR Series — your questions answered
Which JH-CR model does my boat need?
Displacement matters more than length. Lighter monohulls are usually well served by the 3JH40 or 4JH45, mainstream cruising yachts by the 4JH45 or 4JH57, and heavy cruisers, catamarans and displacement motor boats by the 4JH80 or 4JH110. Gearbox ratio and propeller selection are part of the answer too, so we size the package against your actual boat rather than a length chart, and verify it on the water.
Will a JH-CR fit where my old engine sits?
Often, yes — the series is deliberately compact for its output and the JH footprint is what many yachts were designed around, so replacing an older Yanmar GM or JH (or a similar-size competitor engine) is a well-trodden path. Every repower still needs engine beds, shaft alignment or saildrive aperture, exhaust, fuel system and wiring checked, so we inspect the boat before quoting a changeover.
Saildrive or shaft drive?
If your boat already has a saildrive, staying with one is usually the simpler repower — and there's a saildrive path across the whole family: the SD60 pairs with the 3JH40 through 4JH80, and Yanmar's heavier-duty SD15 covers the 4JH80 and 4JH110 for larger monohulls and catamarans. Saildrive gives a quieter, better-aligned installation with less vibration; shaft drive is mechanically simpler, avoids a hull diaphragm and is the standard for motor boats and workboats.
Is a common rail Yanmar harder to look after than my old mechanical one?
Routine servicing is much the same — oil, filters, impellers, anodes and belts on the usual schedule. The difference is the electronically managed injection system, which needs dealer-level diagnostic tools for fault-finding, and cleaner fuel, so good filtration and water separation are worth doing properly at installation. As factory-trained Yanmar dealer technicians, we handle both the routine and the diagnostic side with genuine parts.
Ask about the JH-CR Series range
Tell us your vessel, how you use it, and whether this is a new build or a repower — our team will recommend the right Yanmar JH-CR Series model and drive, with pricing, usually within 1 business day.