Fixing engine on the hard + How long run engine to ensure it works?

[watanaka]

We are currently hauled out and replacing our starter motor. Maybe something we should have waited to do until we were in the water. While getting the starter motor out, a brass fitting on the fuel line going to the engine also broke. I presume at least this means the engine needs to be primed

We are having a diesel mechanic to fix all this in the yard on Monday. Two questions:

-What procedures can a a diesel mechanic do while we are on the hard to ensure it is working? Can he at least ensure the key is turning over the starter motor? (Don't want to be dropped in the water unable to go anywhere).

-Secondly, once we are dropped in the water, how long should I ask to idle there before motoring away? If our engine were to cut out after we motor away we'd smack into land in about 30 seconds. How long would I need to idle to ensure the diesel engine is clean of air, etc?

(We motored 75 nautical miles to this boatyard, so the motor itself should be working fine if the starter and fuel line are fixed).

Thank you for helping out a newbie.

[KDH]

Your mechanic should be able to turn over the engine by removing the raw water intake hose and placing it in a 5 gallon bucket of water, just make sure he does not run the engine dry. You can also run a hose to the bucket to keep filling it while the engine runs. As for warming up your engine I would say 10 minutes will probably be plenty.

[HappyMdRSailor]

Originally Posted by KDH

Your mechanic should be able to turn over the engine by removing the raw water intake hose and placing it in a 5 gallon bucket of water, just make sure he does not run the engine dry. You can also run a hose to the bucket to keep filling it while the engine runs. As for warming up your engine I would say 10 minutes will probably be plenty.

Smart one that KDH... If only for her choice in boats....

The method described is the most common proper one....

[skipmac]

HI Watanaka,

You already got the answer to your question but I have an additional recommendation. Maybe you have already thought of this but just in case.

If you are in a situation where you are motoring and a suddenly dead engine could leave you aground, smashing into a dock or any other unpleasant result you should have your anchor ready for immediate deployment. In fact, it's a good idea to always have an anchor ready for emergencies unless you are offshore.

[Pirate999]

KDH nailed it. 10 min should do it. If your at a yard, I'd splash the boat and start it up. If it doesn't work the mechanic can fix it then and there. That's assuming the yard has work docks.

[watanaka]

<3 you guys

[Hudson Force]

All good information above, but it should be noted that there is not a finite answer to the question. I recently motored for a period of six hours before the accumulated air entering a Raycor filter by way of a pinched O-ring caused my diesel engine to stop. There is no occasion when someone is free from the potential to lose engine power.

[perchance]

Put it in gear at the dock and work the throttle up and down a couple of times just to be sure.

[roverhi]

You can start the engine on the hard without cooling water to be sure that it will start. Running for a minute or less without cooling water won't hurt the raw water pump impeller. If you disconnect the belt to the raw water pump, you could run it for quite a long time at idle without damaging it. I would wait until it's back in the water to be sure its got 'legs', however.

Having an anchor ready for immediate deployment isn't a good idea, you shouldn't ever leave the slip without a readily deployable anchor. You can never tell when something is going to go wrong and the simple act of dropping an anchor can turn a disaster into an inconvenience. Replacing the starter shouldn't effect how the engine runs but you can never tell. Haulout before last for a bottom job, the engine wouldn't turn over when relaunched. No work had been done in or around the engine. Turned out a wire in the engine harness decided that it was a good time to go on a permanent holiday and disabled the starter solenoid. The yards electrician figured out the problem quickly, spliced in a jumper wire to bypass the offending one and we were on our way in a few minutes.

[skipmac]

Originally Posted by CaptForce

All good information above, but it should be noted that there is not a finite answer to the question. I recently motored for a period of six hours before the accumulated air entering a Raycor filter by way of a pinched O-ring caused my diesel engine to stop. There is no occasion when someone is free from the potential to lose engine power.

Absolutely. I once had an engine with some weird problem with the cooling system that would pop up randomly. Sometimes would run for 48 hours straight and then overheat. Sometimes would overheat after an hour. Then goes for a few months without a problem.

So bottom line, you can warm it up and get it running but it still might die unexpectedly. Hence the advise to always keep an anchor rigged.

[Cheechako]

15 mins, some in gear, before leaving the dock, watch the temp gauge too. An engine can often be run on the hard by putting a garden hose in the open top of the raw water strainer with the seacock shut. It's an easy way to fresh flush in the water also. If it overflows a little into the bilge .. no problem.. maybe even good!

[Lake-Effect]

When I was working for a boat mechanic in 2010, we'd always start the engine while on the hard, as part of the spring commissioning (after changing fuel filters, priming, tightening belts etc etc). With one person in the boat and the other on the ground we'd do the following:
- start the engine, should catch in 5 sec or less if the prime is done
- if it starts, we stay at 1000 rpm or less, shift into fwd and confirm prop rotation, shift into reverse, confirm prop rotation, back to neutral, shut off. All in like 15 -20 seconds.

Re impeller - we'd inspect them, change if necessary, and we lightly grease them before putting them back, so the 20 sec of dry spinning did minimal wear to them.

[Jim Cate]

Originally Posted by roverhi

You can start the engine on the hard without cooling water to be sure that it will start. Running for a minute or less without cooling water won't hurt the raw water pump impeller. If you disconnect the belt to the raw water pump, you could run it for quite a long time at idle without damaging it. I would wait until it's back in the water to be sure its got 'legs', however.

While it is true that running dry won't hurt the engine itself, it is quite likely to melt or burn the exhaust hose and waterlift (if it is the typical plastic model). Our exhaust systems are dependent upon the presence of cooling water to avoid self destruction.

But starting up on the hard for long enough to reassure ones self that the repair was successful should be ok.

Cheers,

Jim