Info from the Mack Boring Diesel Instructional Class:

These notes were taken by RCR tech Mike Russell this winter at Yanmar Diesel School:

At the end of every season:

Change fuel filters. The primary fuel filter must be 30micron (red) or the engine will starve for fuel.

- The secondary filter on the engine can be a 10micron (blue) or 2micron (brown).

The secondary filter must be changed at the end of each season. It contains chemically treated filter paper which prevents rust in the injectors.

Take care of your engine, any rust on the engine, fuel lines and especially the oil cooling lines should be sanded and painted with Rustoleum or Yanmar paint.

Be sure to clean up all diesel fuel that is spilled while changing the fuel filters and bleeding the fuel system. Use a 409 or orange type solvent cleaner. Diesel fuel will weaken/breakdown the rubber engine mounts so pay close attention to cleaning them.

It is recommended that the engine coolant/antifreeze should be changed once a year in the southern states and every other season up here in the north. Mack Boring recommends the all Yanmar engines should be using the "extended life" pink or orange in color antifreeze. If you have green, it should be flushed and changed to Texaco pink, Shell Rotella orange or Yanmar antifreeze.

Engine "shutdown" cable should be lubricated each season. Mark end of cable, at shutoff valve, where cable enters shielded casing with "whiteout". Unhook cable from shutoff and slowly pull inner cable from the shield at the helm. Stop pulling out the cable when you see the "whiteout" mark. DO NOT COMPLETELY REMOVE THE CABLE. Wipe the cable down with winch grease and push back into shield. Re-attach to shutoff valve.

Change engine oil and filter at the end of the season. Used oil contains diesel contaminants that will change to acids over the winter and cause engine damage.

- Always use the same oil manufacturer and weight. Mixing manufacturers can cause problems because they each use different processes and slightly different additives. (We should be tagging the engine or always use Yanmar oil)

- Use only Yanmar oil filters. Others (such as the FRAM) may not handle the oil pressure adequately, bypass too easily? Yanmar filters believed to be made by WIX.

- Synthetic oil is not recommended for sailboat engines. They seldom reach operating temperature.

Impellers should be inspected at the end of each season. If you want to extend their useful life you can remove the impeller and soak it in olive oil during the off-season and re-install in the spring. Or just replace in the spring for piece of mind.

Strainer seals should be inspected at the end of each season. A leaking seal may not be apparent but will suck air during operation. Aerated water does not cool as efficiently and may cause overheating problems.

Anti-siphoning valves should be inspected and tested for correct operation each season.

Belts should be inspected and replaced if there is cracking or glazing of the belts. Yanmar belts are high-temp metric belts and should only be replaced with new Yanmar belts.

Top off fuel tanks to prevent condensation buildup.

Check deck fillcap o-rings. O-rings can crack and allow water and contaminants into fuel and drinking water.

Spring startup procedures:

Install impeller

Open thru hulls

Spring startup procedure should be followed anytime the engine sets for more than a few weeks. Here is Mack Borings recommended startup procedure to get engine oil circulated before starting the engine.

- Hold stop button and crank engine for 5 sec.

- Stop and wait 10-15 sec.

- Hold stop button and crank engine for 5 sec…release stop button and start engine

This process is even more important if the engine has a turbo charger.

During the season:

Check engine coolant often. Coolant level should be checked at the "radiator cap", not at the reservoir tank. If there is an air leak between the heat exchanger and the reservoir, fluid levels at the reservoir tank will be incorrect.

On engine startup, idle engine 3-5 min. to warm up before leaving the dock. Also idle the engine 3-5 min. to cool down before shutting down the engine.

Check engine oil level often. On JH engines make sure that the curve of the dipstick goes toward the center of the engine. Also on the JH engine, when the dipstick is removed, wiped off and re-inserted. Wait 45 sec. before removing the stick and reading the oil level. The rubber bushing around the top of the dip stick will push the oil level down in the tube and will indicate a low oil level causing the customer to over fill the engine and potentially cause an engine "runaway" situation.