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I have a 1989 Johnson 50Hp, It has been converted from the original VRO fuel pump to the standard pump part number 438559. All was running fine until the fuel out snapped off 'was a plastic nipple' I contacted the dealer who sent me a new pump with the brass nipples on fuel out and pulse both pumps original parts. Since I have put the new pump on I have had trouble starting the engine and noticed fuel dripping from the bottom of the intake manifold, after reading through the forums i decided to get 2 x card repair kits. After stripping the carbs down cleaning, putting new part on and putting back into the outboard the engine starts idles then dies after 10-20 secs this continues a few times until I'm back to square one no start. I have stripped the carbs again checking float levels etc and all is correct, put back into outboard and same sequence engine starts a few times then dies and fuel starts dripping out the bottom of intake manifold again? Any ideas on the issue? Compression is 125 top carb, 121 lower, spark is good. Any advice would be greatly appreciated.
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It should be impossible for fuel to be dripping out the bottom area of the intake manifold. The cause of that problem needs to be found and corrected. What is/was the cause?
With no intention of insulting your intelligence.... did you by any chance install the carburetor floats upside down? (It happens).
The fuel primer bulb should get hard, when priming, to a point whereas one could stand on that bulb and it would not go down... a slight exaggeration but I'm sure you get my point. Does the fuel primer bulb obtain hold its pressure? (unless the engine is running of course).
Is that "new" fuel pump a three fitting pump.. Fuel In fitting, (Fuel Out fitting, Pressure fitting)... or... a two fitting pump... (Fuel In fitting, Fuel Out fitting) with the operating pressure obtained via a small hole in the back of the pump?
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(Carburetor Float Setting)
(J. Reeves)
With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.
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Compression pf approximately 120 psi is fine.
Remove the spark plugs and do a spark test. The spark on all cylinders should jump a 7/16" air gap with a strong blue lightning like flame... a real SNAP!... Does it?.... NOTE that the air gap is important, nothing else will do!
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(Spark Tester - Home Made)
(J. Reeves)
You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark or build the following:
A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.
Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:
..........X1..........X2
.................X..(grd)
..........X3..........X4
This can obviously be modified to a 6 or 8 cylinder setup tester.
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Let us know what you find. -
Hi Joe
Thanks for your response I appreciate it, I will check all your points and get back to you, the fuel pump is a 3 nipple, Fuel in, Fuel out and pulse.
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