Part of the Yanmar Repair Manuals.
Every one of the 120 pages in this Yanmar 6LY(M)-UTE, 6LY(M)-STE service manual PDF (OEM #HINSHI-H7004) focuses on getting your marine diesel engine running at peak efficiency. You get complete wiring diagrams for tracing faults, along with a heavy-duty troubleshooting section covering everything from sudden stalls to poor exhaust color. Open up the inspection procedures to find step-by-step rebuild paths for your cylinder block, turbocharger, and marine gears. Run the seawater pump water pressure test at exactly 4kg/cm² and verify your thermostat valve-opening temperature hits 76.5±2°C before trusting the cooling system on the water. A dead engine in open water is not an option. Grab this bookmarked download, open it on your tablet in the engine room, and fix it right the first time.
What's Inside This Yanmar 6LY(M)-UTE, 6LY(M)-STE Manual
| System | Pages | Key Topics |
|---|---|---|
| Specifications | 5-7 | Principal Specifications, Identification of Important Parts |
| Performance Curves | 8-9 | Specific Fuel Consumption, Torque, Output |
| Disassembly and Reassembly | 10-34 | Preparation Before Disassembly and Reassembly, Tools and Measurement Instruments, Assembly Procedure |
| Engine Component Inspection | 35-55 | Cylinder Head, Piston and Piston Pin, Connecting Rod, Cylinder Sleeve, Crankshaft and Main Metal, Cam Shaft and Tappet, Timing Gear, Cylinder Block |
| Lubrication & Cooling Systems | 56-69 | Lube Oil System, Cooling Water System |
| Fuel & Electrical Systems | 70-86 | Fuel Oil System, Electrical Equipment |
| Marine Gears & Turbocharger | 87-107 | Marine Gears, Turbocharger |
| Troubleshooting | 108-112 | The Engine Suddenly Stops, Cylinder Output Is Uneven, Poor Exhaust Color, Trouble with the Turbocharger, Trouble with Marine Gear, Miscellaneous Trouble |
| Standard Service Data | 113-117 | Adjustment Data Check Points, Important Reference Data at Assembly |
| Main Bolt and Nut Tightening Torque | 118-119 | General Tightening Torque, Tightening Torques for Marine Gear, Standard Tightening Torque |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Seawater pump water pressure test | 4kg/cm² | p. 63 |
| Oil filter replacement schedule | Every 250 hours | p. 60 |
| Thermostat valve-opening temperature | 76.5±2°C | p. 115 |
| Thermostat valve lift (at 90°C) | 10mm | p. 115 |
| Number of cylinders | 6 | p. 1 |
| Max speed at no load | 3720 ± 25 rpm | p. 5 |
| Min speed at no load | 700 ± 25 rpm | p. 5 |
| Lube oil delivery | ≥5670 at 3200rpm | p. 6 |
| Lube oil pressure | 0.441 ± 0.049 MPa | p. 6 |
| Main bearing cap tightening torque | 24 ± 1 kgf-m | p. 50 |
Yanmar 6LY(M)-UTE, 6LY(M)-STE Common Problems This Manual Covers
Yanmar 6LY(M)-UTE marine diesel engine overheating with intermittent shutdowns during high-speed operation under load
Inspect the thermostat and cooling system components. Test the thermostat in heated water to verify the valve-opening temperature reaches 76.5±2°C as listed on page 115. Replace the unit if it fails to open or if the valve lift measures under 10mm at 90°C.
Manual Section: 6. Standard Service Data p. 115Low engine oil pressure alarm sounding and engine turning over slowly or shutting down completely
Check the lubrication system and verify the oil filter replacement schedule. Replace the oil filter every 250 hours as specified on page 60. Start the engine and verify the lube oil pressure holds steady at 0.441 ± 0.049 MPa at 3000 rpm.
Manual Section: 4. Inspection and Service Procedure for Each Part p. 60Seawater pump leaking from the weep hole and poor exhaust color with thick steam visible
Remove and inspect the seawater pump assembly for internal wear or seal failure. Perform a water pressure test on the water jacket at 4kg/cm² according to the specifications on page 63. Replace the pump seals or the entire housing if pressure drops.
Manual Section: 4. Inspection and Service Procedure for Each Part p. 63Heavy metallic knocking noise from the lower block area during acceleration and uneven cylinder output
Drain the oil and drop the pan to inspect the crankshaft and main bearings. Verify the main bearing cap tightening torque is set to 24 ± 1 kgf-m as detailed on page 50. Replace any scored bearings and re-torque the caps evenly.
Manual Section: 4. Inspection and Service Procedure for Each Part p. 50Frequently Asked Questions
What are the torque specifications for the main bearing bolts, connecting rod bolts, and cylinder head bolts on a
For the 6LY(M)-UTE engine, the main bearing cap bolts (M15) should be tightened to 24±1 kgf·m. Connecting rod bolts (M12) require a tightening torque of 14±0.5 kgf·m. Cylinder head bolts (M14) are tightened in three steps: 11 kgf·m (1st time), 17 kgf·m (2nd time), and 21 kgf·m (3rd time). p. 118
What format is this Yanmar 6LY(M)-UTE, 6LY(M)-STE manual in?
Immediate download of the complete 120-page searchable Service Manual (11 MB). Access it on any device, from a laptop at your desk to a phone in the field.
Is this Yanmar 6LY(M)-UTE, 6LY(M)-STE Service Manual printable?
Yes, print as many copies as you want, and there are no restrictions. Many mechanics print the section they need and bring it to the shop floor.
Does this Yanmar 6LY(M)-UTE, 6LY(M)-STE Service Manual have electrical diagrams?
Included. The Yanmar 6LY(M)-UTE, 6LY(M)-STE Service Manual covers complete wiring harness diagrams, electrical circuits, and connector pinouts.
Reviews
There are no reviews yet.