'75 johnson fuel pump or carbs

[morb]

hi
i have a '75 johnson 70 horse motor i got from my nephew, we took it the other day and it stalled when shifted into gear we had it going for a bit but it only seemed to be at half power or less. he told me when he had it out last week and it ran great, said he had the carbs done but when i looked at it later the spark plugs were loose, so i'm not sure what kind of job the guy did.
i brought it home to putts around with and couldn't get it started, i checked for spark which was good, put in new fuel, then sprayed fuel mix into the carbs and it fired up. i started looking at the fuel pump and disconnected the gas line from the pump to see if it was working. while the hose was off the engine started and ran for a few seconds, i hooked the fuel line back up and it wont start unless you spray fuel into it.
the pump was pushing fuel out but i'm not sure how much it should be pushing out.
so now now i don't know if its the fuel pump or the carbs. does anyone have any ideas?
thanks
ron

 

[jakedaawg]

Start with the basics:

1. Compression test.
2. Air gap spark test @ 7/16", you are looking for a nice strong bright blue snap.
3. Fuel sample out of your tank. You are looking for phasee separation or water in the fuel.

 

[morb]

hi
like i said in my first post i checked spark which was nice and strong, mixed up new gas, i even bought a new battery. i don't have a compression tester but i'm going to borrow one. the thing that baffels me is when i disconnect the fuel line from the out flow end of the fuel pump the motor will start but not when its hooked up to the fuel pump.
the fuel pump is pushing fuel but i'm not sure if it's enough, what kind of flow should i be getting from the pump?