Everything is hot

[JOHN COOKSON]

Once again the often recommended 0-15psi fuel pressure gauge installed between the pump and carb would be very informative. Inexpensive and easy to install [with adapter]. If Don's suggestion is right you would see the pressure drop to near zero from 2-3psi. [Suggest Marshall liquid filled stainless steel w/glass lens]

+1.Make that +1,000.
IMO there is a high probability this thread would have never happened if there was a fuel pressure gauge installed.
When you do the fuel pump work it will be good opportunity to add a fuel pressure gauge.

ex TRUE GRIT

[W2ET]

+1,001.

Bill

[splashlog]

10000+

Three times I have unplugged the hose from the pump and it pumped gas into a cup at great velocity so I wrote it off as good. I did get a pressure gauge but when it arrived it stated clearly that it was not for use with gasoline...I now have something else on order.

For Don; the bottom of the tank is pretty much inline with the top of the engine. The top of the pump is basically flush with the top of the tank. It's the pump that came with the boat (Carter) and so I have never had any reason to suspect it as everything was working great since 2012 until late last season when unexpected shutdowns began. That event sent me down the rabbit hole at which point I figured it was likely a dirty carb as I had never done any service on it at all and seemed the most likely cause, I then moved to look at the coil while at the same time installing EI and thus creating more problems with incorrect timing, and a wiring error.

A few days ago when I ran everything at low idle just so I could move some oil around to do the long overdue oil change, everything was getting hot, including the fuel pump which I thought was odd. So I will now take a closer look at the pump. It makes sense that it might be ok on a cold start and function well for a time, but perhaps could be overheating/failing after some run time. Which would explain why the run time seems to be shorter and shorter with every subsequent attempt.

[JOHN COOKSON]

ANOTHER GUESS

Before you change the oil give us a reading on the dipstick. There may be no oil to change!

ex TRUE GRIT

[Don Moyer]

Fuel supply

When you test the fuel pump, make sure you test it as it is being operated during normal service. For example, if you have an oil pressure safety switch as required by the Coast Guard and you're bypassing it during your test, it could be bad and you wouldn't know it. If you have decent access to your carburetor, a good way to test the pump is to remove the main passage plug and use the pump to move a couple pints of fuel through the entire fuel system and out the bottom of the carburetor into a clean glass jar.

Still on the subject of the pump, is there a 5 amp fuse in the circuit from the positive of the coil to the pump? If not, and the pump is drawing higher than normal current from the positive terminal of the coil (to your observation that the pump is getting hot), it could be limiting the strength of your secondary discharge at the plugs. Don

[Don Moyer]

Fuel supply

Sorry; I muddled a point in my last post. It's very normal to bypass the oil pressure safety switch when troubleshooting a fuel pump. What I should have said is that if that's what you did, leave the oil safety switch bypassed and try to start the engine. If the engine operates normally, the oil pressure safety switch is your problem and you'll need to replace it. Don

[JackConnick]

If the coil gets hot the engine will shut down. The standard install is with the coil hanging on a bolt on the block where it gets very hot.

I had problems where the engine would run about 10 mins, then shut down.

I bought one of Don's high power coils and moved it over to a nearby bulkhead and haven't had any more problems.

Jack

[romantic comedy]

I am not sure where this thread is at currently, but I will tell you how I determine if fuel is not getting to the carb.

I take an outboard can and put it on the deck. Thru the open port light I run the hose to the carb. Pump the bulb and poof you have gas to the carb. I ran it this was for 20 miles at 2000 rpm and 6 knots.

My fuel pump was intermittent and made me crazy.

The other way I initially tried was just filling a one gallon jug and setting that higher then the engine. Put the hose in the jug and run it to the carb.

(this was the only problem I ever had with the Atomic Four, in over 20 years!)

[W2ET]

I am not sure where this thread is at currently, but I will tell you how I determine if fuel is not getting to the carb.

I take an outboard can and put it on the deck. Thru the open port light I run the hose to the carb. Pump the bulb and poof you have gas to the carb. I ran it this was for 20 miles at 2000 rpm and 6 knots.

My fuel pump was intermittent and made me crazy.

The other way I initially tried was just filling a one gallon jug and setting that higher then the engine. Put the hose in the jug and run it to the carb.

(this was the only problem I ever had with the Atomic Four, in over 20 years!)

Hey, RC!

I think I calculated once that the gravity-feed fuel source would have to be something like 10 feet above the carb to match the pressure of the fuel pump, although I remember multiple posts reporting success at deck level.

Bill

[romantic comedy]

Hey, RC!

I think I calculated once that the gravity-feed fuel source would have to be something like 10 feet above the carb to match the pressure of the fuel pump, although I remember multiple posts reporting success at deck level,


Bill

That would makes sense as the fuel pump provides more pressure then needed. Gravity at 2.5 feet above the carb worked fine for me. (good old hydrostatics)

I used gravity on woods cars and dune buggies. Many motorcycles used gravity feed. Generators and power equipment often use gravity. My antique outboards use gravity feed.

[splashlog]

Coughing Blood

Mostly for Don;
I tried your suggestion to test fuel flow through the carb, and it spat out fuel like a 2 year olds prostate.
I have a 0-15PSI fuel rated pressure gauge on it's way.
To my horror I did notice a black ish discharge in the water presumably coming from my exhaust.
I have now swaped out coils, and swaped out carbs and the shutdown still occurs.
There is evidence of water still in the oil (from last years debacle), it was kind of greyish when I checked the level yesterday.

[sastanley]

Be careful changing too many things. if the carb and coil did nothing, I would switch back to the originals and continue testing, especially if the replacements did not improve the issue.

[nyvoyager]

For what it is worth I went down a similar road years ago.
Bought a glass inline fuel filter and installed it before the carb for testing purposes ONLY.
Working my way back to the tank, it first turned out my fuel line from the tank was filled solid with crud (original to the boat).
If allowed to sit, enough fuel would gather to run the engine for awhile.
Then I checked the tank itself and it had a good amount of old varnished fuel particles in it. Pulled the tank and had it cleaned, replaced the fuel lines.
If it is a fuel problem you can test run it from a rigged outboard fuel tank.
The other thing to check is the fuel tank vent making sure it is not clogged.
But none of this explains the overheating and water in the oil.....