Fuel stalling issues on a 49.7 Evinrude

[Picklepower]

I’ve got an Evinrude 49.7 with a few Tim Kurcz modifications done to it. It’s just a fun lake boat and I had it out on the weekend for the first time this year. It ran great for about 10 minutes, I had to shut it of for a couple minutes, it ran great for about a minute or two then it started starving for fuel and quit. It started fine after giving it a little choke and ran again for a minute or two, it did this over and over. I figured out that if I feathered the throttle a bit it would pick up and continue to run until I got back to the dock.
I checked things over, the tank vent was open, there was nothing in the fuel filter or fuel pump screen, I couldn’t check the primer ball as it’s a lay down hydro and it’s at my feet.
Rod

[DeanFHobart]

With an air hose from a compressor, blow out the carburetors... there could be restrictions in the internal passages or jets... how about the fuel pump diaphragm? If the fuel issue has been eliminated from the problem, then it has to be ignition.

[25xs]

Better figure it out... One sure way to have to send it back to Tim for a complete rebuild is to continue running it while it's acting up.

No gas = No Oil to any cylinder being starved. In the mean time, the other two cylinders could care less and will continue pumping the bad cylinder to death.

You can install a tee fitting on the fuel pump outlet and either use a gauge or a small ball valve and test the fuel pressure quickly on the hose in your driveway. Should have 1psi at idle up to 2.5psi at 4500 rpm... Anything even close to this is fine. If you have really weak fuel pressure, then a new fuel pump is cheaper on ebay than an OEM fuel pump rebuild kit. Just replace it. They are $19 to your door.

There is really no reliable way to blow out the carbs with compressed air without disassembling them. That, too, is a pretty easy task and you really should not need any parts to reassemble them (clean) unless you have black colored gaskets (not ethanol resistant) in which case you should get a new gasket set with the tan (ethanol resistant) gaskets.

If you have the fuel primer system (and not choke plates in front of carbs) be sure the red lever on the primer is parallel to the solenoid body.

[mike ross]

we had same issues of engine getting on plane and running out of gas. we went to and electric fuel pump with a pressure regulator. this solved the problem. The other option is duel fuel pumps. be carefull as it is easy to burn a piston if it runs lean on fuel.