Evinrude bogging down when accelerating

I have a 1987 Evinrude 60 vro that from time to time will bog down and turn off when accelerating quickly. I have replaced the fuel line (which has no air leaks) and the fuel filter. I recently used Sea Foam as an engine tuner to decarbonize the motor. Next on my list is rebuilding the fuel pump, but I am not sure if this is necessary. I have found that once the motor heats up a little it is less likely to bog down, and that motors can actually run too cold if the thermostat sticks open. From the time the motor first starts it begins cooling which also leads me to believe the thermostat is not working properly. Thank you in advance for your responses and let me know if I left anything out!!

Re: Evinrude bogging down when accelerating

When it bogs down, have someone pump the bulb and see if it helps. That would indicate a possible fuel pump problem. Did you replace the primer bulb too? Also, it will begin cooling as soon as the engine is started. Nothing odd about that. If you feel it's running too cool, get some thermomelt sticks from the dealer and check the temp. A infrared thermometer would work too..

Re: Evinrude bogging down when accelerating

make sure the timer base is moves without sticking when you advance the throttle. also that the throttle cam hits the roller right on the mark, not before.

Re: Evinrude bogging down when accelerating

yes i did replace the primer bulb as well...and i have also had someone pump the bulb while the motor is bogged down and it had zero effect. The only thing that worked was tapping the choke and this seems to instantly fix the problem. After the motor gets up to speed there is never a problem, only when accelerating. Thank you for your previous suggestions!!

Re: Evinrude bogging down when accelerating

If you can bump the key primer(not a choke) and get the engine to respond a couple of things come to mind.One item would be a fuel restriction in the low speed porting of the carburetors.The carb bowl pickup tube is many times the culprit.Another item would be that the idle mix is a bit on the lean side and needs to be richened up.If your carbs have fixed idle ports and are not adjustable , then consider that a restriction may be within the fixed orifice/s.Another distinct possibility is one mentioned by jtexas refering to the throttle cam roller being exactly aligned with the scribe line of the fiber throttle cam when the controls in in the neutral position.The roller should be aligned on center with the line and 'just touching' when in neutral.Also,all three carb throttle flaps should be fully closed in neutral and exactly horizontal(not past) at full throttle position.

Note: If your carburetors are of the fixed slow speed orifice type,and I believe they are,the orifice is located on the upper front face of the carb body.I believe the orifice is a number 25 or .025" size.