DF90 Ran out of fuel and now won't start, unless I pull a spark plug!

[pjf7395]

I have a DF90 with about 280 hours on it. I have always maintained it, never once gave me a hiccup until the other day.

My fuel gauge was stuck and I inadvertently ran out of gas. No big deal, got the boat back to the dock, fueled it up, pumped the primer bulb to it was hard,turned the key and it would not start.

The engine cranks fine and usually at the start of each crank gives a light cough as though it is going to start.

I thought maybe it was weak spark so I pulled a plug out to check and see what the spark looked like. To my great surprise the motor fired right up and sat there idling on 3 cylinders. I did this with all four cylinders one by one and the results were the same, it would run fine with only three plugs in. Well as fine as a 4 cylinder will run on only 3 cylinders that is.

When I put all four plugs in it goes back to a light cough on occasion but no start.

This is driving me nuts! I have good clean fuel all the way up the pump mounted on the cylinder head, no water or contamination is evident.

Any ideas? Thanks in advance!

[Harper]

What kind of shape is your battery in? Sounds like it might have a problem overcoming the compression with all four cylinders during start. (Grasping at straws, man. )

[pjf7395]

Hey Harper-

Good thought but sadly the battery is fresh and fully charged. It spins over plenty fast!

I can hear the fuel pump do its prime and then shut off, I don't have a check engine light flashing, and there is definitely fuel there. On the times that it does kind of cough as soon as it stops I get two beeps from the dash.

[redlowrey]

[QUOTE=pjf7395;27466]I have a DF90 with about 280 hours on it. I have always maintained it, never once gave me a hiccup until the other day.

My fuel gauge was stuck and I inadvertently ran out of gas. No big deal, got the boat back to the dock, fueled it up, pumped the primer bulb to it was hard,turned the key and it would not start.

The engine cranks fine and usually at the start of each crank gives a light cough as though it is going to start.

I thought maybe it was weak spark so I pulled a plug out to check and see what the spark looked like. To my great surprise the motor fired right up and sat there idling on 3 cylinders. I did this with all four cylinders one by one and the results were the same, it would run fine with only three plugs in. Well as fine as a 4 cylinder will run on only 3 cylinders that is.

When I put all four plugs in it goes back to a light cough on occasion but no start.

This is driving me nuts! I have good clean fuel all the way up the pump mounted on the cylinder head, no water or contamination is evident.

Any ideas? Thanks in advance![/QUOTE'''Were the plugs wet or dry when you removed them, if wet push the warm up leaver to open the throttle, also connect a volt meter to the grey wires at the coils note the voltage with key on and check again while cranking. If the voltage is dropping below 9 volts while cranking there may not be enough secondary voltage produced at the plugs and when you remove one the cranking voltage is a bit higher, put new plugs in anyway.