Engine failure while cruising

[R_p_ryan]

Yesterday when cruising at 1800 RPM my single engine 1978 Mainship 34 shut down. Just prior to shut down the engine surged and hesitated like it was out of fuel.

At the time I was running on the port fuel tank only because I wanted to equalize the volume in both tanks. The starboard tank was at 1/4 full and the port was 3/8 full. I had closed the fuel valve from the starboard tank a few days ago.

I was near a busy shipping channel in deep water so immediately called for Vessel Assist, then went to troubleshoot. I simply opened the valve for the starboard fuel tank and could hear this sucking sound like the fuel line was under a vacuum. Then I was able to restart the engine, and it easily started up. I was on the way to the fuel dock and filled both tanks and everything was fine for the remainder of the trip, approximately three hours. When filling the fuel tank I could feel air coming out of the vent, so I think there's something blocking the line.

Does this mean there is a sludge block in the port tank? The boat gets regular weekly use in a variety of rough to calm waters and the last fuel fill was about five months ago.

I'm taking a bunch of kids out for the Blue Angels air show on Sunday, so I need reliability.

Thanks,
Robert

 

[Capt.Bill11]

Sounds like you may have a blocked line. Open it up at a point down stream of the tank and see if anything comes out. If not or it glows very slow blow it out with compressed air and see if that helps.

 

[Delfin]

Yesterday when cruising at 1800 RPM my single engine 1978 Mainship 34 shut down. Just prior to shut down the engine surged and hesitated like it was out of fuel.

At the time I was running on the port fuel tank only because I wanted to equalize the volume in both tanks. The starboard tank was at 1/4 full and the port was 3/8 full. I had closed the fuel valve from the starboard tank a few days ago.

I was near a busy shipping channel in deep water so immediately called for Vessel Assist, then went to troubleshoot. I simply opened the valve for the starboard fuel tank and could hear this sucking sound like the fuel line was under a vacuum. Then I was able to restart the engine, and it easily started up. I was on the way to the fuel dock and filled both tanks and everything was fine for the remainder of the trip, approximately three hours. When filling the fuel tank I could feel air coming out of the vent, so I think there's something blocking the line.

Does this mean there is a sludge block in the port tank? The boat gets regular weekly use in a variety of rough to calm waters and the last fuel fill was about five months ago.

I'm taking a bunch of kids out for the Blue Angels air show on Sunday, so I need reliability.

Thanks,
Robert

Presumably there is a separate vent to each tank? If not, the single vent sounds like it is off the starboard tank and the port tank was unvented once cut off from the starboard, creating negative pressure and shut down. If they are separately vented, then check to make sure the port vent is clear and if valved, the valve is open. If the vents are all good, you might also check the thread on fuel polishing if this turns out to be crud blocking the pick up line from the port tank. 37 years of usage is plenty of time to build up a fair amount of crud.

 

[sunchaser]

At the time I was running on the port fuel tank only because I wanted to equalize the volume in both tanks. The starboard tank was at 1/4 full and the port was 3/8 full. I had closed the fuel valve from the starboard tank a few days ago. Thanks, Robert

Robert

Have you established where sucking air is on each tank? How do you measure capacity?

Maybe 1/4 is at the bottom of the pickup tube. On many tanks the bottom 1/4 of distance is well less than 25% of volume because the tank bottom is cut to match the hull shape.

 

[gaston]

If I was in that situation and taking precaution I would be taking a 20L portable tank with fuel and fuel line with the ability to gravity feed the engine .

Easy and cheap insurance you will get home

 

[Heron]

Exact same thing happened to me a few weeks back,,,,
Starboard tank would not draw, port was fine. Stopped at a most inopportune time with half a tank of fuel in the tank. . The VERY first thing I did was switch tanks and it started right up. Later I ended up pulling the lines off the distribution 3-way and running some compressed air through the starboard fill.... Whatever it was, cleared itself and has been fine since. I suspect some clogging at the pick-up or fuel line screen...

 

[R_p_ryan]

Great idea. Ill get that setup. I'd like to figure a way to put it on a scale to measure fuel consumption at different RPMs. Suppose I'll have to splice into the fuel return line as well. I'm just kinda paranoid about getting air into the system.

 

[Heron]

Great idea. Ill get that setup. I'd like to figure a way to put it on a scale to measure fuel consumption at different RPMs. Suppose I'll have to splice into the fuel return line as well. I'm just kinda paranoid about getting air into the system.

My earlier post on this....
In my case it's easy to bleed the system with my pump. You can do it manually with a lift pump as well..

I pulled the line at the distribution valve so no air got in from that point to the filters and engine. Once started it pulled fuel and cleared itself. No air issues

http://www.trawlerforum.com/forums/s32/fuel-pick-up-issue-21378.html

 

[R_p_ryan]

Presumably there is a separate vent to each tank? ...

...check the thread on fuel polishing if this turns out to be crud blocking the pick up line from the port tank. 37 years of usage is plenty of time to build up a fair amount of crud.

Yes. Each tank is separately vented and I could feel airflow from the vent when filling the tank.

When I first got the boat a year+ ago I went out in rough water with a buddy in another boat in case the filter clogged and I needed a tow back. The PO hadn't used the boat in several months and avoided anything other than still water. It was amazing the amount black tar that came out and settled in the water traps. Since then I've replaced the filters, gone out in heavy wind chop, and taken the fuel to very low levels and then fully filled the tanks. I guess a nasty clingon finally freed itself and plugged the line. I wonder how many remain. Too bad the access to inside the fuel tank is so limited. I'd like to send some mini robots down there to do some cleaning.

 

[markpierce]

Two years ago, my then-two-year-old boat developed a very slow flow in the fuel-polishing system. Turned out there was a "lint" clog in the line:

 

[Heron]

LOL....This all sounds VERY familiar!

Read this:
http://www.trawlerforum.com/forums/s32/funky-fuel-filters-19536.html

 

[Delfin]

Yes. Each tank is separately vented and I could feel airflow from the vent when filling the tank.

When I first got the boat a year+ ago I went out in rough water with a buddy in another boat in case the filter clogged and I needed a tow back. The PO hadn't used the boat in several months and avoided anything other than still water. It was amazing the amount black tar that came out and settled in the water traps. Since then I've replaced the filters, gone out in heavy wind chop, and taken the fuel to very low levels and then fully filled the tanks. I guess a nasty clingon finally freed itself and plugged the line. I wonder how many remain. Too bad the access to inside the fuel tank is so limited. I'd like to send some mini robots down there to do some cleaning.

Does sound like some diesel booger at the pickup. It could even be some foreign object, like Mark Pierce's cootie or the aluminum seal from a bottle of diesel treat. You might consider getting the tanks professionally cleaned, or install a slightly less expensive polishing system. If you polish when in a sea way with tanks at 1/8 or so, you'll pick up the stuff that would typically cause problems.

 

[FlyWright]

Two years ago, my then-two-year-old boat developed a very slow flow in the fuel-polishing system. Turned out there was a "lint" clog in the line:

... Mark Pierce's cootie ...

OMG!!! A Carquinez Cootie! How perfect is that?

(...only wish I had thought of it, Delfin!)

 

[HopCar]

Mark, I think you've angered a cat and it put a hair ball in your tank. My cats like to leave them where I'll step on them barefoot.


Do you guys have screens on your fuel pick ups? I took mine off. I was once stopped by a bunch of small particles clogging the screen. Removed the screen and the remaining crud was caught by the Racor where it was easy to deal with.

 

[jleonard]

The 1978 Mainships use a rubber hose as a pickup tube in the tanks. They are notorious for de laminating and shutting off the fuel. You can remove the pickup tube from the engine compartment. Pull it and inspect. Replace with plastic.

 

[Nomad Willy]

jleonard,
I'm shocked. I assumed all pick tubes were made of the same material as the tank unless perhaps if it is plastic.

 

[R_p_ryan]

The 1978 Mainships use a rubber hose as a pickup tube in the tanks. They are notorious for de laminating and shutting off the fuel. You can remove the pickup tube from the engine compartment. Pull it and inspect. Replace with plastic.

Jleonard, again you're a source of super info on the Mainship!

 

[R_p_ryan]

If I was in that situation and taking precaution I would be taking a 20L portable tank with fuel and fuel line with the ability to gravity feed the engine .

Easy and cheap insurance you will get home

On my way to O'Reillys to get the supplies. Would a cheap siphon tube with a primer bulb work with diesel, and would you splice that into the lifter pump? There's a spin on filter between the lifter pump and primary pump but no water separator. My fear is introducing air. The Racor is between the distribution valve and lifter pump.

 

[jleonard]

jleonard,
I'm shocked. I assumed all pick tubes were made of the same material as the tank unless perhaps if it is plastic.

After 1978 Mainship used copper tube soldered into the threaded fitting like most other pickup tubes I have seen. Those have issues too.

 

[jleonard]

Tempo makes plastic pickups or at least they did in 99 when I replaced mine

 

[Keysdisease]

Hello Jay of the previous racing Mainship fraternity,

Two other things to consider for Mr Ryan,

The copper tube and valves for the 78' is caveman, and considering what replacements would cost replacing it all would make a good weekend project. Just sh_tcan all that old garbage and replace with new copper and ball valves. I can't tell you how many times I chased down an air leak in that old spaghetti across the aft bulkhead.

If you have a Racor filter the round diffuser in the bottom of the unit where the fuel comes out and spins is hollow and there's a metal ball inside that is probably designed to distribute the fuel evenly. This is raw fuel as it comes from the tank and in my olde '78 the cavity where this ball lives was completely blocked up with the black goo. The bottom of the diffuser just unscrews to give access, check it out.

As previously mentioned, a professional tank cleaning may be well worth the cost. Wait until you have about 1/4 each tank. The guy that did mine had a high pressure nozzle on the return line that caused the hose to whip around inside the tank like an angry snake to stir up the sludge.

Also as previously mentioned I usually carried a 5 Gal Jerry can and had the tubing handy to quickly plumb it into the fuel system in front of the primary filter. Came in handy a couple of times.

Replacing the pick ups is also a good idea, although a little more involved.

My olde MSI stopped running a few times. Every time was for a fuel problem, it was never an engine issue except for throwing a belt which was my fault for bad maintenance.

 

[Capt.Bill11]

The ball in a RACOR acts as a check valve.

 

[Keysdisease]

Hoe exactly does that work as a check valve Bill?

The ball in a RACOR acts as a check valve.

 

[BlueYonder]

This is from Racor:

"The hollow aluminum checkball
floats up against the seal when fuel
is stopped, preventing fuel bleedback.
If unit looses prime, inspect
upstream hose connections first,
disassemble unit to inspect seal and
ball. (It is normal to hear a "rattling"
sound at any time)."

 

[Keysdisease]

That's how I would expect it to work, except it felt solid (heavy) and not hollow from what I remember of the last time I took it apart.

Learn something every day. That said, this cavity is the first place fuel comes into the Racor, and in my olde MSI it was almost solid with black goo, ran great after a good cleaning and a little compressed air through the passages.

This is from Racor:

"The hollow aluminum checkball
floats up against the seal when fuel
is stopped, preventing fuel bleedback.
If unit looses prime, inspect
upstream hose connections first,
disassemble unit to inspect seal and
ball. (It is normal to hear a "rattling"
sound at any time)."