1999 Johnson 50 HP J50PLEEA - won't idle or WOT

[jtlott]

I have a 1999 pontoon with a 50 hp Johnson outboard model J50PLEEA with the VRO/fuel system. I have owned this boat for 14 years. The motor has been setting up for the last 4 years. The motor has less than 150 total hours. I have completed the following in my effort to get her going again:
• Drained and cleaned the fuel tank
• Replaced the tank to engine fuel line and primer bulb (not OEM)
• Replaced fuel filter (not OEM)
• Compression test – cold engine, WOT, top-126, bottom-121
• Replaced the spark plugs
• Checked for spark at both cylinders (not actual spark jump test)
• Drained and flushed carbs with carb cleaner (did not remove and deep clean)
• Temporarily disconnected the oil tank from the VRO/fuel system (plugged the oil line)
The following is what the engine is doing/not doing:
• With a couple squirts of 50:1 fuel/oil mix from squirt bottle she fired up
• Runs good on muffs
• Won’t idle for more than 1 min when in the water
• Runs good at ¼ throttle
• When it dies, won’t start unless primer bulb is squeezed a few times
• When going to WOT it runs for about 1 minute and then bogs down
• When I was squeezing the primer bulb during initial startup, I noticed some bubbles coming out of the fuel pump side of the VRO (air motor housing)
Suggestions as to what the problem(s) could be and what I should do next would be greatly appreciated. Others have suggested the fuel pump is the problem.

[Solarman]

Sounds like carbs need ”deep cleaning”, probably old fuel in pas-sages, jets, needle valves. Need to soak well, and blow out all pas-sages with compressed air.
Also, look into the bubbles at pump?

If not familiar with cleaning carb(s), recording mixture screw settings, dismantling and putting all back together properly, then take to a qualified mechanic.

Good luck.