HELP lehman 120 died on sudden deceleration

Hey guys I have twin 120 H 380 cu.in. Lehman, in close to factory spec. not new but well taken care of. Today all was well doing 1800 and running 8-9 knots for 6 hrs. She was purring along with her sister when I came to a out of nowhere No Wake and like an idiot I cut down fast and washed a little. The port died in 4 sec. the other just keep on. I tried to crank, no go. I have checked all the first problem, fuel (no trash or air) elec. (start switch to alt.) all is as right as I can tell. I had to pull in to get medical assistance so I'll be here till Wednesday morning. we are all poor in some way but I really don't want to pay 175.00hr. if someone on this treasure cove can help. Any Ideas?

I'm in Brunswick, GA heading for Houston and have to be back by Christmas or sleeping in my bed will qualify for Combat pay.

Just to clarify: When you slowed down they both really fell down in RPM and the one did die completely ?

Does each engine run off one tank, Or are they separate (tank for each engine).

Did you recently mess with wiring under the dash? Or on the engines? Secondary Fuel pump?

Does the other engine run fine now?

Any mechanic would change the fuel filters. (All of them). Primary, secondary, one on block.... All of them first. Both sides. When did you last fill up? When did you last check your water separators?

Check your fuel shutoff solenoid-make sure its energized. I'm assuming it will turn over with the starter.

yea, as above, does starter spin over engine as normal?

While you try to start it wiggle the gear lever to make sure it's truly in neutral.

If it still doesn't start you are going to have to go step by step in an orderly fashion to find the fault.

Starting by testing the neutral lock out circuit, make sure the fuel cutout solenoid used to stop the engine is not some how stuck engaged and then moving on to fuel flow.

I would not just start changing fuel filters willy nilly. First use the manual priming pump and see if you have fuel to the injection pump.

Your engine should not stall just because you chop the throttles.

When you slowed could water have gotten up your exhaust and flooded her? (Do you have floppers on your exhaust?)

Throwing that out there ... will hush now.

Edit to add: not flooded. Water aka hydrolock?

And good luck.

ok

It spins normally, yes I would think water washed in ( no flappers) full of fuel polished and the other engine is fine. I checked the throttle and neutral both functional and engaging as designed. I am checking for hydrolock in the morning. All new filters with fill up. I will check the throttle solenoid. Lots of ideas so ill be busy. I will let ya'll know how it goes.

Mike

If the starter spins the engine normally I would think a hydrolock would not be the problem. Is the exhaust run from the lift muffler (I am assuming there is one) to the transom sloped down toward the transom or level? I would be a bit surprised if a wake washing up into your stern would send water all the way up the exhaust hose, through the waterlift muffler, and into the engine, but I guess that would depend entirely on the configuration of the boat's exhaust system.

Also, if you spend some time cranking the engine without having it start as you are determining the problem don't forget that this can fill the exhaust system with raw water since there there won't be any exhaust pushing it out. Depending on the design of the exhaust run this could conceivably cause raw water to build up to the point where it can enter the exhaust manifold and some of the cylinders.

The photo is the exhaust system on our starboard engine. We had this layout designed and fabricated when the system that was on the boat when we bought it began to rust out. Note that the fiberglass lift muffler has a drain at the bottom that can be used to free the muffler of water if for some reason the engine has to be turned over in multiple attempts without starting.

Fuel. In fact I'll bet if it's not a filter it's the lift pump. They fail. Do you have an electric pump inline for bleeding? If so, start it and check for flow after the secondary filter. Crack a line. If no electric, crack the same line and hand pump the lift pump. Let us know?

With the fuel supply camp of thought with one more twist.

If it is cranking normally and the fuel stop cutoff is in the normal run position, nothing sucked into or over the air inrake...then my bet is then air in the fuel system.

Tighten all fittings from tank/manifold to fuel pump, then bleed from same point all the way to injector pump.

I have had a loose fitting on the pump cause a no start situation.

I am with the last two posters but lean towards the fuel pump. Better check your oil level too. If the lift pump is bad it may be filling the crankcase.

Yup, if the other things are checked ok, sounds like a fuel flow or a fuel pressure issue. Cracked line, fuel supply pump or loose fitting maybe. Hopefully not an injection pump, (more spends.) systematically check the easy and less expensive things first.

I would not mess with the filters just yet as that just adds unnecessary variables. If the filters were dirty and not allowing fuel to flow you would notice this at speed where fuel flow is higher due to engine demands as opposed to idle (most of the time engines run fine at idle with clogged filters at first but won't flow enough fuel to run at cruse speed).

I would go through a complete step by step bleeding, first at the on engine filters all the way to the rack and then several injectors. If you don't have copy of the written bleeding procedure get one, by the time you do this you should know the condition of your fuel pump and it's ability to flow fuel and the entire fuel systems ability to flow fuel to the injectors.

If this works great, but something is not right with Mr. Henry, the engine should not have stopped when you reduced the throttle so don't just be merrily on your way, you have had what we call a hint of things to come and the next time Mr. Murphy will most likely be aboard.

Ye Oldie mechanical diesels that are running fine one min, then die (quietly without trauma, ie not mechanically) are 99.8% of the time fuel related.

Capt.Bill11 said:

While you try to start it wiggle the gear lever to make sure it's truly in neutral.

If it still doesn't start you are going to have to go step by step in an orderly fashion to find the fault.

Starting by testing the neutral lock out circuit, make sure the fuel cutout solenoid used to stop the engine is not some how stuck engaged and then moving on to fuel flow.

I would not just start changing fuel filters willy nilly. First use the manual priming pump and see if you have fuel to the injection pump.

Your engine should not stall just because you chop the throttles.

Click to expand...

if the lift muffler is full of water it will not start, to much back pressure?

capt jerry said:

if the lift muffler is full of water it will not start, to much back pressure?

Click to expand...

Highly unlikely.

Bill is right. Furthermore, excess cranking can fill the muffler with water and eventually back-fill into the cylinders so be cautious. Back pressure will not inhibit a start. Just re-stating.

Until you can get it to start, close sea cock. Once you get it sorted, open it back up, AND DON'T FORGET!! This will keep muffler from overfilling while cranking and that can back flood engine with water.

My vote too is for air in fuel or failed stupid lift pump. Try a bleed and see what you get. Good Luck!!

Capt.Bill11 said:

Highly unlikely.

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had it happen to me the mufller got full of water and the engine would turn over but would not start. this was on a 671 dd drained the muf and it cranked right up.the reason the muf filled up was from loading a fuel tank on one side and the other one was empty and the boat was leaning way over and the sae water came up the exaust and filled the lift muf up but not the engine. pulled the plug on the lift muf drained it and fired right up . so it ims possible?

capt jerry said:

had it happen to me the mufller got full of water and the engine would turn over but would not start. this was on a 671 dd drained the muf and it cranked right up.the reason the muf filled up was from loading a fuel tank on one side and the other one was empty and the boat was leaning way over and the sae water came up the exaust and filled the lift muf up but not the engine. pulled the plug on the lift muf drained it and fired right up . so it ims possible?

Click to expand...

Highly unlikely in this case.

Marin said:

The photo is the exhaust system on our starboard engine. We had this layout designed and fabricated when the system that was on the boat when we bought it began to rust out. Note that the fiberglass lift muffler has a drain at the bottom that can be used to free the muffler of water if for some reason the engine has to be turned over in multiple attempts without starting.

Click to expand...

I am interested in that drain at the bottom of your water lift muffler. I too have a Vernier and like the idea of being able to drain it. How'd you do that? Anything I need to know about the fitting?

And thanks..

capt jerry said:

had it happen to me the mufller got full of water and the engine would turn over but would not start. this was on a 671 dd drained the muf and it cranked right up.the reason the muf filled up was from loading a fuel tank on one side and the other one was empty and the boat was leaning way over and the sae water came up the exaust and filled the lift muf up but not the engine. pulled the plug on the lift muf drained it and fired right up . so it ims possible?

Click to expand...

This is a unique problem with a DD two stroke. If muffler is full when cranking, the scavenging blower at cranking speed leaks by enough that it cannot create enough pressure to blow out the muffler. Causes a no-start. Common in Vikings and other DD boats with water lift mufflers.

This problem will NOT occur with a four stroke. They will blow plenty hard on exhaust stroke to purge the muffler.

janice142 said:

I am interested in that drain at the bottom of your water lift muffler. I too have a Vernier and like the idea of being able to drain it. How'd you do that? Anything I need to know about the fitting?

And thanks..

Click to expand...

The fiberglass water lift mufflers on our boat were custom made by Unicraft Marine Products in Bellingham, WA. The company has more recently moved up the road a bit to Ferndale and has changed its name to MJ Marine Exhaust Systems.

We were told by the diesel shop that designed our new exhaust layout, had the mufflers made and installed them that they will last more or less forever.

Unicraft installed drains as a matter of course; I can't speak for MJ Marine Exhaust Systems but I would assume they do, too. The originals were petcocks as shown in my photo. I have not yet had occasion to actually use one but every year or so I'd give them a twist to make sure they still worked.

After a bunch of years I twisted one and it rotated in its barrel instead of screwing open. So I contacted Unicraft and asked if the drain could be replaced. The owner told me that he no longer used the petcock design in large part because of what I had just experienced. Instead he had switched to a simple stainless screw-in plug design. He came to the boat and installed the new-type drain in both our mufflers at no charge.

Marin said:

Instead he had switched to a simple stainless screw-in plug design. He came to the boat and installed the new-type drain in both our mufflers at no charge.

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Our Ceteks have a drain plug also. Gosh Marin, the Northern WA and BC builders are super, we've heard similar stories about Magnum, Norhtern Lights, Hurricane and Nick Jackson.

janice142 said:

I am interested in that drain at the bottom of your water lift muffler. I too have a Vernier and like the idea of being able to drain it. How'd you do that? Anything I need to know about the fitting?

And thanks..

Click to expand...

Just drill and tap the muffler. Then put a plug or a ball valve in. I wouldn't use a petcock.

Thank you gents. I suspect this is a Good Idea and inexpensive. Two of my favorites!

Forgive me for going slightly off thread but 120 Ford Lehman's are the topic of conversation
We used several Ford 120's for driving pumps and compressors and noticed when doing daily oil checks the oil level instead of going down, began to rise slowly.
We found 2 causes,
1 was a cracked excess fuel pipe which runs between the injectors under the rocker cover, the joins are brazed and work harden, if they crack they cause a fuel leak, which being under the rocker cover, drains into the oil.
2, A perforated diaphragm seal on the lift pump will also cause the same symptoms.


I hope these tips are helpful.

Anything I need to know about the fitting?

The ones I have seen use a std pipe plug .

No hassle to get a pipe to hose fitting and run a good hose to a ball valve for winterizing or just draining.

Remember just sitting the muffler is a source of sea water in constant contact with the engine and what ever cylinder is open.

I like Capt Bill's suggestions.

I find it hard to believe that all these more complicated problems crop up all of a sudden just by chopping the throttles.

Why has no one mentioned checking for fuel at the injectors before fixing stuff???

Xsbank said:

Bill is right. Furthermore, excess cranking can fill the muffler with water and eventually back-fill into the cylinders so be cautious. Back pressure will not inhibit a start. Just re-stating.

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i beg to differ, close the exaust pipe on you car and see if it will run???? if air cant get out it will not come in , to much back pressure?????????????