Feul Line vacume

[xchange]

I've gota a Johnson 40 &#4

I've gota a Johnson 40 (late 90's vintage) that actually runs great (or it did last year). it idles great and without load I can rev the heck out of it by pressing the throttle on the carbs. Under load bogs down very bad. Found a baddly cracked vacume line on lower carb and replaced. Ran smoother but still bogged down under load. I noticed the fuel line from the external tank has a vacume created in it once this happens (actually in the primer bulb). Tank Air inlet is clear and open and both ball valves work properly. sometimes I hear a spring or something release in the carb area and the vacume goes away but soon returns.

any ideas how to resolve?

 

[haffiman37]

"A bit confusing, but let us t

"A bit confusing, but let us try to clear it out. By 'late 90' I would not actually call it a vintage. In that case You probably have a VRO engine with separate oil tank. The 'click' You hear in the carb area I think is comming from the air motor in the VRO pump,and at idle it should be around every 30 second. When You mention 'vacum' in the fuel line, does the bulb go flat or just a bit soft? There was an issue with some of the OMC Dura tanks and the ventilation back in the 90es, but I do not remember excact Year, but is was an o-ring/seal not allowing the proper ventilation and the pick up units had to be changed. Try to take the quick connector off the hose at tank end and put the hose straight into the tank. If problem disappears, change the pick up unit or the tank."