Looking after engines and genset during extended refit

[ColinCattanach]

Hi all, our Leopard 46 is in a shed for some extended repairs and a refit. Are there any specific precautions you would recommend we should take to keep the engines and genset healthy for the next couple of months? Nothing will freeze, (we are just starting Autumn in NZ so not very cold).

I understand we may be best to prime the intake systems with water when we splash again to avoid damaging the dry impeller but anything else?

Thanks in advance

[skipperpete]

Originally Posted by ColinCattanach

Hi all, our Leopard 46 is in a shed for some extended repairs and a refit. Are there any specific precautions you would recommend we should take to keep the engines and genset healthy for the next couple of months? Nothing will freeze, (we are just starting Autumn in NZ so not very cold).

I understand we may be best to prime the intake systems with water when we splash again to avoid damaging the dry impeller but anything else?

Thanks in advance

A couple of months is on the borderline between a full storage layup and a short stay layup but from my direct experience the biggest problems come from having the exhaust hose connected to a partially full aqualock, the humidity in that part of the exhaust can cause corrosion in the cylinders that have open exhaust valves so either disconnect the the hose at the mixer elbow or perhaps drain the aqualock. Raw water pump impellers take a set that conforms with the cam in the pump and often the impeller never returns to its original shape…. It’s easy to just take em out, bag em and zip tie the bag to the pump. Finally, I do a lot of work on engines that won’t start after a layup because of injector pump problems caused by waxy fuel gluing the pumping elements in place or by moisture in the fuel causing corrosion within the elements. The no start is mildly annoying and usually involves sending the pump to a fuel injection tech for repair but the other scenario is where the pump has a stuck plunger in the full fuel position and if you’re not ready, this can be way beyond annoying as the engine goes overspeed It only happens with cassette and inline multi element pumps and easily predictable by loosening off the injector pipes and spinning the engine over till you see fuel at the loose connections …THEN , pull the engine stop and continue cranking ….. no fuel should be coming out of the connections and that means the stop control is working so no overspeed is possible. This situation is difficult to predict or prevent, worse in Europe with high wax fuel and common where there’s water lying in the bottom of a fuel tank undetected and some long layups on large engines involve replacing the fuel in the injector pump with high quality dry calibration fluid. Some yachting folks use liquimoly products to achieve a pump flush and preserve , others just leave the system alone with old fuel in the pump.

[purvisgs]

Looking after any trapped saltwater & the exhaust elbow is a good/important point, often a little inaccessible/unique to each install.

For anything you can gain access to in the exhaust area, the intake, anything rusty, all fasteners, and anything that moves (externally) I subscribe to and have had good luck with the practice of "fogging everything" , just spray down with "oil" (lubricating, penetrating, fogging, etc oil --of whatever type) and call it good, basically.

Best practice typically to top off the fuel tanks (air space will condense out water in temp changes) - and why not add a somewhat heavy dose of snake oil diesel fuel additives and run it so they are in the system at shutdown- if possible. Make sure you have a real fuel filter (ex 10 micron, racor WITH water separator), a spare filter on hand upon launch, and be aware most issues after storage would come from water in fuel. But several months to 1year old diesel in most cases is of course still fine no issues there unless you get bad fuel.

For much longer periods of storage say 3+ years, disconnect & run the fuel lines directly off a can (or a HEAVY dose mixed in a can of fuel) of "diesel purge" (or similar, in the old days perhaps ATF type F) before shut down, (importantly cap off fuel lines for storage) and spray some fogging oil down the intake - as preventative to address some of the potential sticking IP issues mentioned above.

Disassemble the water pump/s and clean/lube impeller if deemed necessary, or depending upon how accessible they are. Check zincs. Address corrosion.