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As the title says.

I have a 13HP diesel inboard that runs great, however, when I go over a large swell or wake it will die. Any thoughts? If I had to guess I would say the intake is coming out of the water. Any thoughts on repair would also be appreciated.
 

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Losing your cooling water intake on a wave wouldn't/shouldn't stall the engine. In any event intakes are unlikely to be in an area that is readily exposed in normal wave/swell conditions and you'd likely be unaware of such momentary interruptions.

I'd be looking into your fuel tank, sludge and/or water at the bottom of the tank being picked up in sloshing conditions, but even that wouldn't happen necessarily 'on the wave'.. it would take quite a few seconds to starve the engine.

Another possibility if you have an electric fuel cutoff is a loose/intermittent connection.

More detail on the boat/motor combo would help.

Take a second to read this:

http://www.sailnet.com/forums/introduce-yourself/119081-new-sailnet-help-us-help-you.html
 

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As the title says.

I have a 13HP diesel inboard that runs great, however, when I go over a large swell or wake it will die. Any thoughts? If I had to guess I would say the intake is coming out of the water. Any thoughts on repair would also be appreciated.
In addition to what Faster offered, maybe something loose falling in to/on to the air intake tract? I have read about people finding a small piece of rag floating around the tank which was sucked up into the feed pipe and the after the engine stopped it would sink back to the bottom of the tank to be sucked up again later.

Maybe something in the tank vent pipe? Although that probably wouldn't stop the engine immediately. Saw a picture of a dead rat in a Honda air filter box? Let us know what you find.

Paul T
 

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What about air getting in to the fuel supply hose in the tank due to the sloshing around? Depending upon the size, shape, and fill level the fuel intake might get uncovered for a little bit allowing air to get in which would turn the engine off.

When the engine cuts off, does it sputter or just die? Does it slowly lose power and then die? Do you have a full tank or 1/2 full, or ???

Maybe gunk is getting in the engine, clogging up the filter?

My money is on the air bubbles.


Mandolin, Bayfield 36 out of Rock Creek, Chesapeake Bay.

Sent from my iPhone using Tapatalk
 

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Your symptoms are quite similar to a fuel delivery system (piping/tubing) that has become loaded with WATER. Water will seek out the LOWEST section and settle out in the lowest portion of the TUBING. If this was air accumulating in the fuel delivery system, you'd probably have the engine 'stumble', lose rpm and then finally stall; since you state 'cut out' Id make the bet that trapped WATER is being 'released' into the injector pump then on to the injectors. Your job is to now find out WHERE these slugs of WATER are being 'stored'. A big 'slug' of water hitting the injectors will cause immediate 'cut out' (and sometimes shatter the injector tips/pintles, etc.).

What to look for:
1. your MAIN filtration (Racors, etc.) integral WATER SUMP 'should' be located at the VERY LOWEST LEVEL of the entire fuel circuit. If the main filtration 'set' is higher than the lowest 'run' of tubing ... and the system shows or has evidence of free (visible) water there is a very good possibility that the water has 'overwhelmed' the capacity of the 'sump' and has migrated beyond the sump into the the tubing that is 'lower' than the 'racor filters'.
1a. If so, I suggest that you 'carefully' open and remove the 'filter' from the engine mounted 'guard' filter (never considered a part of the main filter 'set', its only there in case some goes wrong with the MAIN filters) ....[slowly/U] remove the filter element from the 'guard' filter, then take a syringe (with tubing added to the tip of the syringe, and suck out a bit of 'fluid'). What youre looking for is the phase separation between oil and water. Also when opening the 'guard' filter check for any AIR that has become trapped in the top of the filter housing.
1b.If yes (water found in the guard filter housing) then drain (blow out) ethe ENTIRE fuel delivery system and relocate the Racor, etc. filters to the VERY lowest possible place down IN THE BILGE. You may want to install a 'drain cockvalve with tubing' at the bottom of the 'racors' to make water drainage easier and less messy.
If water found in the guard filter, remove the injectors and send them to an 'injector shop' to be checked/rebuilt. Every town with a population over 20,000 has an 'injector shop'.

If NO water is found, get back to us and I can outline what to do etc. to trace an intermittent large AIR leak in the fuel delivery tubing .... very common especially if the system has 'compression' fittings.
Also indicate if this engine ever used so-called "bio-fuel", especially the notorious "reclaimed bio-fuel".

;-)
 
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