Monday 15 March 2021

Winter Maintenance in Gosport #2

Hi everyone,

More maintenance in an exotic location.  As liveaboards there are no constraints on the work we can do during the Covid-19 lockdown.  Our to-do list before departure from the UK is shrinking fast.

Job Done

We installed our Craftsman CM3.27 engine in Thailand in 2014.  The blog post is here.  The engine has been great.  The only problems we've had were an overheat due to a failed impeller, a failed exhaust temperature sensor and an overheat last year probably due to an airlock forming in a nasty seaway.  But the engine is now 7 years old and we're about to resume bluewater cruising.

In February we received a box full of engine parts.  This included new hoses, starter motor, alternator, impellers V belts, heat exchanger seals and a full set of sensors.  They didn't all go into a spares locker.  We wanted to fit the new hoses, starter motor and alternator.

New Parts

Step one was to dump out the old coolant.  We do that regularly and it's an easy job.

Coolant Out

Next we removed and replaced two hoses.  One runs from the raw water pump to the heat exchanger.  The other runs from the fresh water (coolant) pump to the heat exchanger.

Hoses old & new

Next we removed the old alternator.  The new unit was different to the original and we noticed the electrical connections and connectors differed.

Old Alternator connections

New Alternator Connections

We didn't immediately fit the new alternator so as to have better access to the starter motor and heat exchanger.

Replacing the starter motor was simple, but only because we have very long socket driver extension bars and a universal joint.  They made it very easy.

New Starter Motor

Then the job got harder.  We wanted to check the heat exchanger tube stack.  The end caps have never been off since the manual doesn't include their removal in the maintenance schedule.  In the end I realised it was a workshop job and we don't have one of those aboard.

Marine Tech weren't interested in the work so I contacted N Evans Marine Services.  Nathaniel was able to visit within a few days.  He removed the heat exchanger assembly and took it away for disassembly.  Taking the assembly off allowed us to check for carbon deposits in the exhaust ports and at the entry to the mixing elbow.  Very little to be seen which is great after 7 years and 1150 hours of operation.

Heat Exchanger Off

Nathaniel had quite a job getting the forward end cap off since there's no 'lip' t0 help lever it off.  With the end caps off a couple of impeller vanes were visible.   They've been there since the 2015 overheat at Reunion Island.

The tube stack came out easily but the ends were pink, indicating corrosion.  And the tubes were partially blocked.

Impeller vanes and tube stack (N Evans photo)

Tube stack corrosion and deposits

Based on the corrosion we wanted to replace the tube stack.  However there were none in the UK and getting one here from Craftsman's base in the Netherlands proved impossible.  The post-Brexit goods flow from the EU to the UK is a mess.  We even checked if the US or Australian agents had one in-country but sadly they didn't.

After waiting several weeks in case the situation improved we gave up and had Nathaniel clean the old tube stack and reassemble the heat exchanger.  He then refitted it aboard, I fitted the new alternator and we test ran the engine.  That was last week.  Today we gave the engine a good run in the pen, including under load for 30 minutes at cruising revs.

Job Done!

Very pleased to have new hoses, starter motor and alternator.  We'll fit a new tube stack at the earliest opportunity.

Besides the engine we've ticked off a number of jobs...

  • Purchased a second OceanSignal RescueMe MOB1
  • Replaced the battery on our first MOB1
  • Tested both MOB1 DSC and AIS transmissions
  • Replaced our 10-year old Bosch drill
  • Restocked batteries, glues, lubricants etc
  • Started stocking canned and dry foods
  • Multiple major stowage reorganisations
  • Gave away now-irrelevant Baltic and Norway cruising guides
  • Purchased cruising guides and electronic charts for new exciting areas!

Trust all's well where you are!