Which standard engine came in the Malö 36, and what common weaknesses should I check?
I'm looking at a Malö 36 with its original Yanmar diesel, but the advert doesn't give the exact model. Which engine should it have, and what engine or boat weaknesses should I concentrate on before buying?
Answer
The Malö 36 normally came with a naturally aspirated, three-cylinder Yanmar 3JH-series diesel of roughly 40 hp, driving a conventional propeller shaft. Check the engine identification plate, as the exact version depends on build year and any replacement, then concentrate on the exhaust and cooling system, shaft installation, ageing deck fittings and teak.
Identify the engine
Earlier examples commonly have the Yanmar 3JH2E, usually quoted at 38 hp, while later boats can have the 3JH3E or 3JH4E, generally advertised at about 40 hp. This is a guide, not a confirmed factory changeover schedule. Establish the individual boat's specification from its plate, serial number and original paperwork.
Photograph the engine and gearbox plates and check them against service invoices. An advert saying simply "Yanmar 40" does not tell you which impeller, exhaust elbow or service manual you need. These engines use freshwater cooling: coolant circulates through the block, while seawater passes through the heat exchanger and then into the exhaust.
Service history matters more than a low hour reading. Look for regular oil and filter changes, coolant changes, impeller replacement and attention to the exhaust elbow. An old hour meter may have stopped or been replaced.
Inspect exhaust and cooling
Pay particular attention to the seawater-injection exhaust elbow. Internal corrosion and deposits can restrict the exhaust or cooling-water passage even when the outside looks sound. This is a concern with ageing marine diesels, not evidence that every Malö 36 has a defective engine.
- Exhaust elbow: look for rust trails, leaks at joints and evidence of removal or replacement. If its history is unknown, have it removed for internal inspection.
- Raw-water pump: check for salt deposits and drips around the shaft seal. Ask when the impeller was changed and whether the old one had all its blades.
- Heat exchanger: inspect end caps, hose connections and surrounding metal for corrosion or dried coolant. Missing impeller fragments can lodge upstream of the tube stack.
- Exhaust hose and waterlock: check for cracking, chafe, soft patches and insecure supports, especially where access is awkward.
Keep hands, clothing and tools clear of belts and the rotating shaft while the engine is running.