1990 Johnson 6hp fuel pump or carb?

[freebledsoe]

I picked up a 1990 6 horse Johnson this year for a kicker. It ran once, really well... then started acting like it wasn't getting fuel. Right now it's unuseable, and I'm trying to figure out what the issue is. First, it turns out the gas in the tank that came with it was old, and may have caused a gunk buildup in the carb. Just a possibility. I pulled both spark plugs and they were coated in a thin varnish but still looked decent. I replaced them to see if it made a difference.

With new plugs, it still won't run. But, before the new plugs it wouldn't even act like it would start when I tried starting fluid sprayed in the carb. With new plugs it will run briefly on the ether. 

I disconnected the safety/kill switch to see if it was preventing the motor from running, no change. Fuel hoses all look good. So I'm thinking either fuel pump or carb kit next, and I have experience rebuilding carbs so my question is more centered on the fuel pump. It's on the side of the block, and has a large headed screw right in the center of it with a flat screwdriver slot and knurled on the outside, like a quarter or dime is. If I turn this screw  out a half turn (or less) fuel starts leaking out from the thread area and seems under a little pressure. Is this normal, or does it indicate a bad diaphram or gasket?

[Cliff Wagenbach]

There is a very good chance that the carb. needs a kit and the fuel pump diaphram is coated with hardened gas film.

If the motor starts and runs on starter fluid the engine is probably good. Those motors are hard to kill!

Have one myself! 1966 model.

Cliff

[Surface Tension]

That screw isn't an adjustment, it holds the fuel pump together. 

  First determine if you have a choke or primer.  Primer meaning each time you pull out the choke rod and push it back in a shot of fuel is delivered.  If your not doing that and just pulling out the rod like you would a choke then it won't start.

 So you will have to check and while your looking make sure the linkage to which ever you have (choke or primer)is connected.

 If the bowl on the carb has fuel in it and you choke or prime it, it should fire.  

 

 If that all checks out and still no fire then you need to be sure there is fuel filling the bowl.

Two things will stop this.

A stuck needle and seat/fuel inlet valve.

Bad hose fitting, often the seals deteriorate and block fuel flow.

In both cases you will notice a the primer bulb is hard because of the blockage but no fuel in the carbs bowl.