motor suddenly dies

[HalcyonS]

Hi all
I'm sure this question - or variants thereof - has been asked 100 times.

I've been having the occasional dead stop while motoring over recent weeks. In the past, waiting a minute and starting has worked. Yesterday, came to a dead stop, and wouldn't restart. Well not exactly - it gave a little rumble, but wouldn't run. Thereafter, couldn't get a cough out of it. Plenty of battery, plenty of spark, just replaced plugs and its been running stronger than ever. The only difference yesterday was I had a friend at the helm and he ran the motor a bit harder than I do, ie 2000rpm instead of 1500.

I have a cannister filter (fitted by seller when I purchased the boat seven years ago), a priming bulb, a polishing filter (new), upstream of a 2 yr old facet fuel pump. Works fine afaik. copper line to Carb (which was new, also fitted by seller). I'm guessing grit in carb jet and there is a carb rebuild coming up.
Question 1- under normal circumstances, how often should one rebuild the carb?
Question 2 - given the age, whcih parts should I get from MMI - just the gaskets?
Question 3- is there a carb overhaul faq? I searched 'carb' and 'carburetor' in the faq search and came up with nothing.
Question4 - Is mine standard? see pic of carb
Questoin 5 - does my diagnosis sound ok? Any other ideas?
thx
Simon

[JOHN COOKSON]

Was the shutdown(s) sudden like the key was turned off or more gradual and sputtering like the engine was running out of fuel?
Here are a couple of ideas for further diagnosis:
Are the spark plugs wet with fuel after a period of no start cranking?
Check for spark immediately after a shut down by putting a lead on a spark plug outside the engine holding it on the engine to ground turn the engine with the starter and check for spark.
Off the top of my head a "sudden dead stop" sounds more electrical than fuel related.
You can bypass the boats wiring with a jumper wire to coil+ from the big battery terminal on the starter motor.
Remember to keep the feed water valve to the water pump closed when you no start crank.

TRUE GRIT

Edit: Back to the fuel side.
Before you take the carb off the engine do this:
Let the plumbing loose between the fuel pump and the carb turn the key on and short across the OPSS to see if you are pumping fuel to the carb.

[edwardc]

I've been having the occasional dead stop while motoring over recent weeks. In the past, waiting a minute and starting has worked. Yesterday, came to a dead stop, and wouldn't restart. Well not exactly - it gave a little rumble, but wouldn't run. Thereafter, couldn't get a cough out of it. Plenty of battery, plenty of spark, just replaced plugs and its been running stronger than ever. The only difference yesterday was I had a friend at the helm and he ran the motor a bit harder than I do, ie 2000rpm instead of 1500....

Abrupt shutdowns are usually electrical, but the rest of your symptoms sound like fuel starvation. Especially the "gave a little rumble, but wouldn't run" part.

Assuming it's fuel, this could be another instance of the "stuck check valve" in the Facett pump. I had similar symptoms a few years ago. It's easy (but messy) to check. Use a socket wrench on the nut-shaped boss on the bottom of the fuel pump to remove the bottom. It's a bayonet style attachment, so it will just turn a small amount and then come off. BE SURE to have something under it to catch the gas!

Once open, remove the small basket strainer if it doesn't drop off with the bottom cover. The bottom of the check valve ball is exposed. Press it gently with a fingertip. It should easily and smoothly move upward against the internal spring. If it doesn't move, apply a little more force. It should come free with a "click" and then move freely.

Unfortunately, if it was stuck, this only a temporary fix. It will run fine for a while, but will eventually get stuck again. The only real cure is to replace the pump.

As for your questions:

1) Some do it every season, I find that more than I need. YMMV
2) If you need it, and Moyer has it, get it from them. You'll be sure it's the right stuff. Gaskets are the main thing though.
3) I believe Moyer sells a carb video. There's tons of advice in the forum, but it'll require a little digging with the search function to find it.
4) Looks like a standard late-model Zenith 5-bolt carb.
5) Float valve is another likely place to find debris & gunk obstructing fuel flow.

[yeahjohn]

There is another 'sudden stopping' thread right now. You could have a coil issue. It is cheap and easy to replace coil so might want to try that first. Your carburetor is very nice, looks new, you have the the modern 5 bolt carb which is cool. It also looks like you have gas leaking from scavenge tube and main jet screw (just saying).

Moyer has a video section, buy the carb video, it will show you the basics, once you open carb it should be obvious if you have a issue. I have had to clean my carb often but lots of people never need to touch it, it all depends on your fuel. Replacing the water separator and polishing filter can be done as often as you want, or feel needed (every season, every oil change, etc). All cheap preventative maintenance I do rather ofter.

[ndutton]

Simon, I'm not seeing much diagnosis yet, just a lot of maybe's.
Here are my two questions that will point us in the proper direction:

1. It's important to know if there's fuel in the carb bowl. Removal of the main passage plug with a catchment underneath will determine that.
2. You said there was plenty of spark. How was that determined, actual testing at the point of shutdown or a deduction it must be good with the recent excellent performance?

[Marian Claire]

Long shot. You mentioned having a squeeze bulb. I chased a intermittent shut down only to find my squeeze bulb was sticking and preventing fuel flow. Some times running at higher RPM brought on the shutdown other times it was just a time issue. The bulbs are cheap and do not last. Is the bulb flaccid after a shut down? After reading how others have set up a switched bypass of the OPSS I plan to remove the bulb and prime the system when needed with the electric pump/switch set up. One less thing to deal with. On your carb pic. Is there a leak at the scavenge tube? Dan S/V Marian Claire

Edit: 2/26/13 "squeeze bulb" removed. Changed the large fuel filter while at it and the electric pump filled the system in 20+- seconds. If you do not have a switch for the OPSS bypass, make sure you attach the jumper wire first, then turn the key. Less chance for sparks. Dan S/V Marian Claire

[HalcyonS]

thankyou all for helpful suggestions!


John -

"Was the shutdown(s) sudden like the key was turned off or more gradual and sputtering like the engine was running out of fuel?"

shutdown is always sudden. In the past, a try soon after has worked first time (suggesting not coil, and debris moved in carb). Monday, a second try gave a short sputter (suggesting fuel blockage). but an hour or more later, no start (again counter-indicating coil problem).

"You can bypass the boats wiring with a jumper wire to coil+ from the big battery terminal on the starter motor."

hmmm, I don't totally trust my wiring harness - its original, and was extremely well made (builder was an engineer) but it is 40 years old. Erg, I've been avoiding that job.

"Let the plumbing loose between the fuel pump and the carb turn the key on and short across the OPSS to see if you are pumping fuel to the carb. "

OPSS would be Oil Pressure Shuttoff Switch, no doubt. Sounds like a potentially explosive test, but I get the idea. Thanks for the other diagnostic tips ie wet plug and spark.

Edward -
"Abrupt shutdowns are usually electrical, but the rest of your symptoms sound like fuel starvation."

that's my strong intuition...

"Assuming it's fuel, this could be another instance of the "stuck check valve" in the Facett pump."

hmmm, I had the pump off recently, I was a bit suspicious of it, even thought its only 2 years old. I noticed the strainer is a bit deformed, and the sealing gasket on the 'cap' was leaving some rubber particles. This is one reason why I suspect fuel blockage. My polisher filter is upstream of the pump as the line from pump to carb is hard copper and I didn't want to cut it.

YMMV - YAAA (Yet Another Afourian Acronym

Yeahjohn -
"There is another 'sudden stopping' thread right now."

I know, I read it, I'm bearing it in mind, but I don't think the symptoms match, ie, it won't start when the coil has cooled.

"It also looks like you have gas leaking from scavenge tube and main jet screw (just saying). "

I know. I saw it, and the seepage from the plug on the block, in the pic. I have tight access - I can get my camera there but not my eyeball

Neil -

" It's important to know if there's fuel in the carb bowl. Removal of the main passage plug with a catchment underneath will determine that."

will do. Might reveal some junk too.

" You said there was plenty of spark. How was that determined, actual testing at the point of shutdown or a deduction it must be good with the recent excellent performance?"

deduction I'm afraid.

Dan -

" I chased a intermittent shut down only to find my squeeze bulb was sticking and preventing fuel flow. "

nice catch!

"The bulbs are cheap and do not last."

hmmm, mine has been on a few years. Time for a change I think.

" Is the bulb flaccid after a shut down? "

no, quite firm and inflated

" After reading how others have set up a switched bypass of the OPSS I plan to remove the bulb and prime the system when needed with the electric pump/switch set up. "

I missed this thread... Surely you'd need a separate switched supply to the pump? (so you wouldn't be turning the engine over? Nice idea.

"Is there a leak at the scavenge tube?" the tube from the spark arrestor? looks like it see remark above about cameras and eyeballs. There is literally 6"-8" between the engine and the engine bay wall.

Thanks all for helpful suggestions. Here's my to-do list-
check for wet plug
check for spark
check for gas in float bowl
check for operational fuel pump
check for stuck fuel pump ball valve
change pump bulb.
pull carb and clean
think about wiring
think about separate fuel pump power circuit with switch
I think I'll get a set of gaskets and do a carb clean, just for my own peace of mind if nothing else.

Simon

[Marian Claire]

Oops. I missed that yeahjohn had asked about the scavenge tube. I see a discoloration on the oil pan just below/behind where the choke cable outer housing is attached to the carb and also some "shiny" stuff on the actual fitting that connects the scavenge tube to the throat of the carb. This probable has nothing to do with the shut down. Dan S/V Marian Claire

[joe_db]

OK - time for my public service announcement. These are VERY DANGEROUS if used on inboard boats
They were never designed to be used below. I have had them pop pinhole leaks AND get the checkvalves stuck either open or closed.

Long shot. You mentioned having a squeeze bulb. I chased a intermittent shut down only to find my squeeze bulb was sticking and preventing fuel flow. Some times running at higher RPM brought on the shutdown other times it was just a time issue. The bulbs are cheap and do not last. Is the bulb flaccid after a shut down? After reading how others have set up a switched bypass of the OPSS I plan to remove the bulb and prime the system when needed with the electric pump/switch set up. One less thing to deal with. On your carb pic. Is there a leak at the scavenge tube? Dan S/V Marian Claire

[edwardc]

Joe,

+1 on that! I constantly had trouble with squeeze bulbs on the outboard on my previous boat.

With an electronic fuel pump, you should never need the priming bulb. Mine will prime through an empty upstream Sierra spin-on filter in a matter of 10-15 sec.

[sastanley]

go the 5 bolt

I know that Don Moyer recommends a squeeze bulb, and I dutifully put one on the first year I owned the boat..I have since removed it. Even with the longer than average fuel line run and a Racor filter on my C-30, I can prime a dry fuel line by hand with my mechanical pump priming bale in less than 30 seconds.

How long has it been since you cleaned the 7 years ago seller installed filter?

To answer your question about a "standard carb": You do have the elusive and rare 5 bolt carb... - that doesn't really mean anything except that yours has a not-very-common 5th bolt just behind the flame arrestor to hold the two halves together.

[Bold Rascal]

Divide and conquer

My fuel system gave me fits so as suggested did some test running with an outboard motor tank, hose and squeeze bulb directly to the carb, bypassing everything while ensuring the carb was not the culprit.

The carb was a mess and got cleaned/re-built. Problem solved? Noooo

From there it was a matter of working backwards thru the fuel system untill the continuing problem was at least isolated. Ultimately I found air leaks in the rubber fuel hose, a crack at a flare connection on the copper fuel line and ultimately a pinhole leak in the fuel tank pick-up tube at about the 12 gallon level.

[HalcyonS]

Can anyone recommend someone who has gaskets for the elusive 5 bolt carb in LA/long beach/Costa mesa area…And what do I ask for?

Mike -
thanks for the nightmare story, kinda makes me wonder why we bother…

Shawn -
"How long has it been since you cleaned the 7 years ago seller installed filter?"

cannister and polishing filter changed every year. The seller's goons took out the original racor and copper lines and fitted a cannister


"I know that Don Moyer recommends a squeeze bulb,"

yeah, that's where I got the idea. I can see taking it off when I fit the electric pump auxiliary power and switch.

Ed
"With an electronic fuel pump, you should never need the priming bulb."

but until I fit the switch, I don't want to kill the battery turning the motor over until the fuel is there (I run the fuel line dry at the end of the day. )

thanks all.

[sastanley]

Halcyon, you for sure can get the 5-bolt carb gasket from Moyer....us not so fortunate guys with the 4-bolt still get the 5-bolt gasket when we order one and it performs fine. I think a whole pile of gaskets, as long as they are under 1 lbs. would cost the same as shipping one gasket at 0.02 lbs., distance not in the equation. ..so at least make a gasket list and then call Ken at Moyer parts..he'll give you the details. I am also sure we can help you find some more stuff to buy in their catalog..

That being said, I have a local marina, who's mechanic is listed on the good-guys list here at Moyer (Billy from Zahniser's) and they still sell some A4 parts...they are between me and my boat!!! , so I patronize them when I can as well as Moyer. You may find some place local to you that sells parts, but you may need part numbers from Universal for them to cross reference.

[ndutton]

About that 4 bolt carb

I rebuilt my carb last night. After reassembly I was alarmed to see light between the upper and lower halves where the 5th bolt would be if I had a 5 bolt carb. I disassembled it and did a dry fit without the gasket, float removed. The halves teetered on the forward bolt area. I went after the high points with a file and improved matters but decided Permatex was necessary just to be sure.

I've either never had the problem before or perhaps more accurately never noticed it. That 5th bolt could have made a difference.