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Blue Crab · 26-01-2014, 17:09

My PO ( a diesel mechanic) mentioned that I couldn't run the Yanmar 2GM while refueling. I don't get why. I have a fill port, a pickup port, a vent with a T ftg for the fuel return line.

I don't see why I can't fill the tank while engine runs. Does this make sense?

colemj · 26-01-2014, 17:13

The only way I could see it mattering is if the tank was very empty and filling it caused a lot of air to foam the fuel and this air found its way into the pickup.

But how onerous is it to shut of the engine anyway?

Mark

Vasco · 26-01-2014, 17:16

What does your mechanic say the reason is. Quite often I've topped up my tank while motoring.

Blue Crab · 26-01-2014, 18:51

I'm doing my best not to talk to the guy for a couple of reasons. As far as expertise goes, the OP is the real deal, I think. He's with the big CAT dealer here. Still, I don't see how it could suck air beyond Mark's scenario.

This whole diesel stuff is new to me. Maybe it doesn't matter but I've operated a lot of machines and turning them off often resulted in great difficulty getting them going again.

My 2GM has ~500hrs. I'm probably worrying about nothing.

markpierce · 26-01-2014, 19:04

Never saw a need to run the engine while docked at a fuel station. Regardless, with engine enclosed and fuel entry on deck, can't imagine the harm.

Pato · 26-01-2014, 19:23

Quote:

Originally Posted by Blue Crab

My PO ( a diesel mechanic) mentioned that I couldn't run the Yanmar 2GM while refueling. I don't get why. I have a fill port, a pickup port, a vent with a T ftg for the fuel return line.

I don't see why I can't fill the tank while engine runs. Does this make sense?

I would imagine it is because you have a tee fitting in the vent/return so when filling the air will push the fuel being returned up and out the vent or cause other spit back issues

glenn.225 · 26-01-2014, 20:31

Quote:

Originally Posted by Pato

I would imagine it is because you have a tee fitting in the vent/return so when filling the air will push the fuel being returned up and out the vent or cause other spit back issues

That would be the only reason that I could see, unless the fuel guy didn't like it.

When I installed my diesel tank tank I only had one fitting for return/vent so I made a T-fitting with a drop tube down to about 3/4 dept of tank for fuel return and open at top of tank for vent. Like this.
Well you get the idea, I work better in metal than new drawing software. BTW it was done in DIA (it's free) just got it yesterday but it seems nice. Similar to MS Visio.

jackdale · 26-01-2014, 20:35

Quote:

Originally Posted by markpierce

Never saw a need to run the engine while docked at a fuel station. Regardless, with engine enclosed and fuel entry on deck, can't imagine the harm.

Stopping the engine for refueling at a fuel dock is the law in Canada.

Where else?

sailorboy1 · 27-01-2014, 03:42

its' like running with scissors

Blue Crab · 27-01-2014, 04:37

Thanks all. The fact that fuel could spit out the vent is enough for concern. I started thinking about it based on the recent similar thread about topping off underway.

thinwater · 27-01-2014, 05:30

Quote:

Originally Posted by jackdale

Stopping the engine for refueling at a fuel dock is the law in Canada.

Where else?

Everywhere. It is also generally illegal to leave the fueling point (get back in your car or wonder).

Many folks believe this is an ignition hazard and is only related to gasoline. That is not true. A MAJOR reason for the rule is that folks (cars, tankers, boats) are more likely to pull off and forget the filler line if the engine is running. I've seen this happen at 500 gpm. It's not pretty. Starting the engine should also help them to think if they are ready to go (disconnected).

sww914 · 27-01-2014, 05:32

I've done it, but we just bought 30 gallons or whatever, not topping it up. Nothing more to report.

S/V Alchemy · 27-01-2014, 06:43

Quote:

Originally Posted by markpierce

Never saw a need to run the engine while docked at a fuel station. Regardless, with engine enclosed and fuel entry on deck, can't imagine the harm.

I can. Glugging diesel into a tank from which fuel is being drawn could a) stir up sediments and tax the filter (although you have a problem if your tanks are this dirty), or b) introduce in the form of air bubbles a series of wee diesel embolisms into the line.

I see few compelling reasons to leave the engine running during a fuel up, and can imagine probably more reasons than I've thought of to consider it sub-optimal.

captain58sailin · 27-01-2014, 07:43

If your system is so weak that you are afraid to shut down your engine when refueling, you have some work to do. As a rule every fuel dock I have ever been to, requires you to shut down before refueling. It might not apply because of you, but the guy next to you that is filling up his gas boat. Your engine is a heat & ignition source.