Engine cutting in rough seas

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Matata

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We have just bought a second hand sigma 33 with a new plastic diesel fuel tank. All has been well installed. The last owner says it never missed a beat except once with a third full and very rough seas it briefly suffered fuel starvation and the engine cut . Turned the key and it was away again. Any suggestions how to prevent this in the future? Thanks as ever
 
I suffered for 18 months an engine, new volvo which cut out on Mersey after leaving Manchester ship canal from winter in Northwich, eventually replaced fuel pump, still cut out, towed three times by Liverpool rescue, motored all the way to the bar light on the third occassion before it stopped, sailed back to the marina in the dark, eventually got to Pwllheli,then after several months of trouble free it packed up leaving Portmadoc in a chop. Decided to rip out all the pipes etc because it was obviously fuel starvation, we disconnected the outlet from the botttom of the diesel tank, nothing came out /forums/images/graemlins/mad.gif poked a stick in and out it flowed /forums/images/graemlins/smile.gif we had a BUG and the black sludge was acting like a flap valve, the engine would run like clockwork until we hit a chop, then obviously the agitated sludge was being sucked over the outlet, causing immediate engine stoppage /forums/images/graemlins/frown.gif tank removed and steam cleaned /forums/images/graemlins/smile.gif ( I heard of someone who had a difficlt to diagnose car problem, that turned out to be a 'leaf' in the petrol tank /forums/images/graemlins/laugh.gif
 
Sailed on Sigma 33 for many years. Dont know the boat but the name is familiar. Have you had a gander at the website ??? Plenty of info on there. 20HP is big for a 33.
 
What web sites had you in mind? Some are half built and never got any further. The tank and tubing are spotless so I feel its some type of pick up problem. Does anyone out there use in line hoppers or baffles in the tanks? Ta so far. ps love the boat!
 
Sounds like crap in the tank, stirred up by bad weather and sucked into inlet. When engine stops suction on pipe stops hence engine restarts.
Suggest thorough cleaning of tank, Separator and replace primary filter.
OOPS tabernacles is a better description than mine
 
Phone Jo. Shes a bit of a bossy bit*h but full of good info for any probs. As far as 33's go she is the man /forums/images/graemlins/grin.gif
 
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The last owner says it never missed a beat except once with a third full and very rough seas it briefly suffered fuel starvation and the engine cut .

[/ QUOTE ]How did the owner know that the cause was fuel starvation? That's always the most likely reason for a diesel to stop but it isn't the only possibility. What is the engine stop arrangement on that engine? Could it have been actuated accidentally in those very rough seas? If he had a large following sea, with some designs of exhaust, if transom-fitted, it can be possible for water to be forced back up through the exhaust and into the engine.
 
Yes - I had that problem with a plastic tank last season. They have no internal baffle. Rough seas throw the fuel about so much that air is drawn into intake pipe and you get an air-lock.
Solved by bleeding, which is easy with a BETA - unless you are still in the rough seas, or by keeping tank full - not always possible.
I spoke with manufacturer and it seems there is no easy solution.
Ken
 
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beta 20 Harmony. Don't tell me you know it!!!!

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I was about to ask the same question! If the boat had been called 'Matata' that would have explained the problems.
 
This engine is said to have started immediately, on the key. Had it been an airlock it would probably have needed bleeding manually.
 
I spoke with manufacturer and it seems there is no easy solution
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The easiest solution is to fit a decent tank with internal baffles. Failing that feed the tank outlet into a small gravity feed tank below it.(bean can size only) You can make one out of any robust container or have one welded up out of steel. It should have "tank in" at the top and "to engine" at the bottom and an "air bleed" at the top lead to atmosphere above the top of the original tank. This will ensure no air bubbles in your fuel line. If the tank is fitted so low you can't do this and you can't raise it up then you need a better tank with internal baffles to stop the "slosh"
 
I agree, the proper solution is a baffled tank.
I've had this problem of the engine cutting out in heavy weather and it can be quite dangerous because you tend to be using the engine when running into port, just when a failure can be most unfortunate.
If the tank is clean you could try extending the pick-up tube closer to the bottom of the tank but be aware that you are more likely to pick up sludge when the tank does get dirty.
 
"gravity feed tank below it."

Thanks, Mike, but a gravity feed tank fed by a siphon effect (plastic tanks have take-off lines from the top) is doomed to failure as soon as air gets into the line - I did say "no easy solution".
ken /forums/images/graemlins/frown.gif
 
I cured this on my Impala by fitting a small sump to the bottom of the tank. This consited of a 1inch brass skin fitting with a piece of brass plate soldered over the end. The fuel pickup was then extended into the sump, so has much less chance of drawing in air, even when motorsailing in choppy seas. You do need good filters as any water tends to be picked out of the tank immediately.
But then I would prefer to remove the water and crud from the tank before it breeds anyway.
Another wheeze is to add another filter upside down (bowl upwards) either low in the pipe or after the lift pump. This will collect the air where it can be bled later. Didn't try this but would like to know if anyone else has. I'm talking about an extra filter, not compromising the engine fine filter btw.
cheers,
chris
 
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