Emergency Engine Start

[FlyingAloha]

Aloha

83 Hunter 34. Perfect running 3GMF Yanmar. Was sailing off a mooring ball, under sail. No motor running. Had an emergency decision to make due to a friends wrong decision. There was zero time to get down and turn the water intake valve open. By the time i was in control and somewhat out of harms way I then remembered in the chaos that I was not pushing water threw the motor.
The motor was run for about 3 min only on coolant.
THAT WAS ISSUE ONE.
Sailed with motor off for about 2 hours.
Then started motor with valve open. Ran fine. No smoke , smell , water flowing.
// Not sure if i damaged anything yet// just back from the trip

+++SECOND ISSUE===

Upon docking on the the next early morning on sunrise , i took my eye off the depth gauge. I sail into an extremely shallow creek where the boat is docked.
Ran her into the mud.
I did not reverse nor put more pressure by throttling up. I was at a low rpm. I felt the boat sludge threw.
I then noticed immediately a big bellow of Thick Black smoke from the exhaust.
Again not sure of the damage yet.

But i did notice what looked like black particle coming from the water line out the back.

Im thinking I sucked the black mud threw the water box intake ?
Shes not pissing water as well as she use too ?

ANy leads on where i should look and diagnose ?

Cheers

 

[Bob R.]

Check the raw water impeller. Could have been damaged running dry then pumping mud.

 

[kloudie1]

Probably toasted the raw water impeller. Open it and replace.. Missing blades will slow the flow.. If you don't find the blades in the pump body, they will have lodged in the input side of the exchanger. . that can make for less flow like missing blades.. Black smoke may (or may not) be that the engine was loaded at low rpm and the governor was over fueling during the mucking through..
Here, the deepest parts of the lake are only 12 feet.. there is a lot of shallow water around and it is not too unusual to have to plow through a bit of muck when exploring a bayou..

 

[jibes138]

Do you have a raw water intake filter/strainer? If you do it is likely all clogged with mud and all the debris within the mud. If you don't have a strainer then that gunk was likely pumped into the tubes of your heat exchanger. Drain the engine coolant, Pull the hoses and remove the heat exchanger. Flush all hoses clean, remove end caps from HX and flush it out to clean it. A stiff wire or small caliber gun brush might be useful to clean the tubes. Muffler might be full of mud and goo, pull those hoses and flush that too. Quite the conundrum Eh? Also the mixing elbow in the exhaust system might be clogged up, flush the raw water tube and fitting, might have to remove the elbow to give it a good cleaning.

 

[dlochner]

The impeller is toast. Don’t close the raw water intake. If you maintain the sea coke and keep the hose in good shape the odds of sinking due to a failed seacock ore low.

 

[FlyingAloha]

Probably toasted the raw water impeller. Open it and replace.. Missing blades will slow the flow.. If you don't find the blades in the pump body, they will have lodged in the input side of the exchanger. . that can make for less flow like missing blades.. Black smoke may (or may not) be that the engine was loaded at low rpm and the governor was over fueling during the mucking through..
Here, the deepest parts of the lake are only 12 feet.. there is a lot of shallow water around and it is not too unusual to have to plow through a bit of muck when exploring a bayou..

right on I will dive into

Do you have a raw water intake filter/strainer? If you do it is likely all clogged with mud and all the debris within the mud. If you don't have a strainer then that gunk was likely pumped into the tubes of your heat exchanger. Drain the engine coolant, Pull the hoses and remove the heat exchanger. Flush all hoses clean, remove end caps from HX and flush it out to clean it. A stiff wire or small caliber gun brush might be useful to clean the tubes. Muffler might be full of mud and goo, pull those hoses and flush that too. Quite the conundrum Eh? Also the mixing elbow in the exhaust system might be clogged up, flush the raw water tube and fitting, might have to remove the elbow to give it a good cleaning.

So i do not currently have a secondary filter installed at this current time. i just removed the old one before the trip. mine was on its way out housing was falling apart , was planning on installing it while i was on the trip. Kicking myself but it is what it is. I will tomorrow go threw what you guys have suggested. This forum is such a great help ! Have my gun brushes. Will stay up past my bed time reading into all of this. QUESTION ..... I just naturally think I should have the intake valve CLOSED as i start this diagnosis work ?

 

[ggrizzard]

Yes, close the valve and check the impeller before running the engine again.
Closing the raw water thru-hull is a safer bet, IMHO. It's not just the valve failing you need to be concerned with. It's also the hose clamps (you got two on there, right?)
and the hose itself possibly failing.
Just put the ignition key on the handle of the valve from now on and you won't forget to open the valve in the future.

 

[kloudie1]

Yup.. closed ..the pump is a foot below the waterline so water will enter freely when you remove the raw water hoses to remove the pump.. unless the valve is closed.. If you didn't go into reverse and put a lot of power on, chances are that there is no significant mud fouling in the heat exchanger tubes.. If a good cleaning and brush out of the tubes hasn't been done that you know of, this would be a good time to do that..

 

[FlyingAloha]

Yes, close the valve and check the impeller before running the engine again.
Closing the raw water thru-hull is a safer bet, IMHO. It's not just the valve failing you need to be concerned with. It's also the hose clamps (you got two on there, right?)
and the hose itself possibly failing.
Just put the ignition key on the handle of the valve from now on and you won't forget to open the valve in the future.

it wasn't "forgetfulness" it was a decision to start the motor for immediate Thrust to avoid a collision. Had I jumped below , moved the mattress , sail bag etc and get to the valve , well Id probably have a jetski inside my boat.

 

[FlyingAloha]

Yup.. closed ..the pump is a foot below the waterline so water will enter freely when you remove the raw water hoses to remove the pump.. unless the valve is closed.. If you didn't go into reverse and put a lot of power on, chances are that there is no significant mud fouling in the heat exchanger tubes.. If a good cleaning and brush out of the tubes hasn't been done that you know of, this would be a good time to do that..

Again THANK YOU for the advice and help ! will update

 

[rgranger]

 

[Rich Stidger]

When you check your impeller- If you have blades missing, be sure to get all of the broken blade pieces. Usually they go out the outlet of the pump, but one time I had an impeller blade go back into the intake of the pump. If you don't check and if there is a piece in the intake, you will destroy the new impeller as soon as the piece in the intake comes loose and goes into the pump.

So be sure to check. If there is a piece in the intake, it won't be very far away from the pump. If you can't find all the pieces in the outlet, run a piece of wire out the outlet and all the way to the heat exchanger. Be sure that you can't feel any obstruction from a broken blade. Usually a blade in the heat exchanger will cause no problems. When I rebuilt my genset I cleaned out an accumulation of broken blades and never had a bad effect from them.

 

[Benny17441]

Don't blame the occurrence on a crew member; everything that happens on the boat is the Captain's responsibility. If you close the raw water intake valve you should hang the engine key on the handle so when retrieving the key you do not forget to open the valve. Like others have said running the impeller dry could have damaged or broken some of the vanes of the impeller reducing the pump's capacity. Black smoke could be a result of an abrupt increase in the engine's load as the Governor System may have over compensated. Equate the occurrence to an overfueling condition on a fouled propeller. That should pose no problem so just inspect the impeller and replace if needed and you should be fine. If any of the vanes are broken make sure to look for the broken pieces to avoid blockages in the cooling lines and passages.

 

[FlyingAloha]

This for sure does not seem to be the correct hose ? looks like a great way to restrict flow. Any part number for this hose as it seems to need a custom bent shape or perhaps a longer run hose ?

 

[kloudie1]

Nope, not the correct hose.. It should have a higher vented loop on the back wall of the engine box. New hose should be run without a kink, which is apparent in that picture.. hose diameter is correct as it carries only raw water. This shot shows the set-up on the H-34. Hose from back of exchanger to vented loop then hose from loop to elbow. Prevents back siphoning from exhaust to engine. cylinders..

 

[Scott T-Bird]

Nope, not the correct hose.. It should have a higher vented loop on the back wall of the engine box. New hose should be run without a kink, which is apparent in that picture.. hose diameter is correct as it carries only raw water. This shot shows the set-up on the H-34. Hose from back of exchanger to vented loop then hose from loop to elbow. Prevents back siphoning from exhaust to engine. cylinders..
View attachment 155580

Of course you know the H-34 exhaust system, but if there is a waterlock muffler system in place, is it necessary to install the vented loop?

FlyingAloha, it's your boat, your choice, but you can make tighter bends without collapsing the hose if you use a wire-reinforced hose, such as Trident Series 100/250. That would be my recommendation.

 

[kloudie1]

I hear ya, Scott.. but the 34 did not come with a water lift muffler.. There is a horizontal cylindrical fiberglass muffler .. again original but ya don't know whether his boat has had that changed.. The original exhaust outlet is under the stern counter and as soon as any speed is on, sail or power, the stern squats and the outlet is submerged.. again, probably not a high risk of back flooding .. There was/is an original high loop in the exhaust hose just before the outlet.. but not a worry I want to have..
Like it is, his boat.. his choice..

 

[Scott T-Bird]

The vented loop that is installed in your photo looks like a very good installation and certainly serves the purpose!

 

[kloudie1]

I scratched my head a bit thinking I'd take the loop out of the system but ended up convincing myself to leave it in.. The valve had stuck open and made a mess with salt water all over the back of the engine.. now, it is on my list to check and I haven't had a problem since.. Amazing how much "stuff" one is forced to learn when ya start dealing with a good old boat!

 

[JamesG161]

ended up convincing myself to leave it in

Good move...

Especially if you don't shut the sea cock soon after engine shuts down. Closing the sea cock will stop a siphon.

If your flex impeller is even slightly worn, you can siphon back into your engine's open exhaust valve.
The amount of back flow depends difference of the boat's water line and the top of your engine.
Jim..