2000, Johnson 50 hp fuel flow problem

The outboard will run when first started for hours. Then if you stop, and I only have done this when we stopped for between 1 and 2 hours, when you restart it will run a brief time (underway) and stop. Pump the bulb and restart it will run about the same time period and stop. However, keep pumping the bulb and it'll run indefinently. Any ideas on what to try and in what order?

Thanks

Re: 2000, Johnson 50 hp fuel flow problem

Generally, when you are pumping the primer bulb you have become the fuel pump. Like I said, Generally, it is time to rebuild or replace the fuel pump.

However, your does run well during the first trip of the day.

That's curious. I would not rebuild/replace the pump without checking and testing the hoses and connections first.

It is possible that as the motor warms the fuel line fitting at the inlet side of the pump softens just enough that the pump then sucks air instead of fuel, then your pumping the primer is simply providing fuel to the pump.

Squeeze the primer bulb firmly and observe all fuel connections for ANY leakage, even the tiniest seepage is NOT allowed.

Check all the fuel lines at the motor for age/fuel deterioration, replace if necessary.

Test the fuel pump flow by disconnecting the carb side fuel line, direct it into a suitable container, crank motor and observe the fuel stream.

Re: 2000, Johnson 50 hp fuel flow problem

I had a similar problem today with one additional circumstance. After several long runs today I encountered the motor wanting to shut down until I pumped on the bulb which was very soft each time. The additional problem was a no oil alarm which would return each time it was reset. I put oil in the gas tank and continued to the landing having to pump the bulb every few minutes. Any ideas?

Re: 2000, Johnson 50 hp fuel flow problem

Pumping the bulb, as said, points to a bad fuel pump. That's where I would begin.

MAS

Re: 2000, Johnson 50 hp fuel flow problem

pumping the bulb could mean many things, air leak in fuel line and connections, partially clogged pick up in tank, clogged vent fuel tank. sticking needle valve in carb.
or a weak fuel pump. i think is would be check these other things, before i spend $400 on a pump, or convert the motor to a pre mixed pump $60.00.

Re: 2000, Johnson 50 hp fuel flow problem

Could The Problem With The Fuel Flow Impact The "no Oil" Alarm? They Occurred Almost Simultaneously. Thanks For The Info Guys, Any Feedback Is Much Appreciated!

Re: 2000, Johnson 50 hp fuel flow problem

Check the vacumn hose from the block to the VRO pump. Some of these engines did not have the notch ground into the starter cap, lower end. The cap would rub a hole in the hose. Most of the time the hole was close to the nipple in the block. The only sensor that will affect engine running is overheat sensor. The low oil and no oil only give a warning alarm.