'89 evinrude 90hp flooding in one cylinder

[Ericmaroney]

Hello

I have a '89 evinrude 90 hp that is flooding out in one cylinder. When the engine is first started, it runs on all four cylinders but as it idles for a little bit (anywhere from 10-60 seconds), one of the bottom cylinders floods out. I'm not sure if it has happened to the top cylinders but the bottom for sure. I recently took the carbs off and cleaned them and they seemed to be very clean and in good condition. I just replaced the spark plugs and 2 of the coils. I have good, strong spark on all four cylinders. When I take the plugs out, the top plugs are clean but the bottom ones are almost always black. Why is this? The carb seems to be the exact same as the top one so it doesnt make sense that is would be running rich but maybe I'm wrong. What is causing one of cylinders to flood out?

I also have a grey foam in the hub of my prop. I wouldn't be too worried about it but the amount of foam is a little nerve-wracking. Does anyone know what is causing this?

I think it is also important to mention I am still using the original VRO pump. One of my initial thoughts is that it is pumping too much oil. Does anyone know how to test the vro pump?

 

[racerone]

The bottom 2 cylinders are fed by the same carburetor.-----It is nearly impossible for one cylinder to flood due to a sticky float / valve.----But if you are running with a conventional pump that one cylinder could flood due to a ruptured diaphragm in the pump.--------But wait----First do a compression test on that motor.-----Then test for spark that will jump a gap of 3/8" or more on the bottom 2 leads.-----And are you sure the bottom 2 cylinder leads are not shorting to the cowling latches ?

 

[Ericmaroney]

I took the carb out and took it apart and there was a tiny piece of plastic stuck in the float valve.. makes sense because this caused it to get too much gas and flood out on the bottom cylinders. Problem fixed! Thanks for the advice!

P.s. I did end up disabling the vro pump. Runs a lot cleaner with the correct oil/fuel mixture.