2004 Johnson 50 bogging down

[Regulator23]

Hi, it’s model J50PLSRS. It’s on a pontoon boat. If I idle around (less than 1500 or so, it runs fine (even for an hour or more). When I open it up, it runs fine for 4 or 5 minutes then immediately slows way down and almost wants to stall. I can keep it running but then it will only idle again. I am trying to nail down if it’s fuel or electric in order to try and fix it. I have replaced fuel filter, it has good gas, and prior to it doing this, it ran great all the time. ANy ideas would be appreciated.

 

[stork55]

Try squeezing the primer bulb when it does this and see if it picks up rpm,check the o ring in the fuel line end to make sure its alright.Also check and make sure your fuel tank is venting.Of course do the basic troubleshooting, compression and make sure spark jumps a 3/8 gap