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200hp Mercury Black Max Bog

Posted: Jun 08, 2012 10:23 am
by VLP
I am new to all of this so please bear with me, I may be asking a stupid question, but from my searching so far I have not run into a conclusive suggestion as to why this is happening.
I have a 1980 Vking with a 200 hp Merc Black Max. It is a premix. Motor idles great and cruises at half throttle perfectly, but if you crank it to WOT it starts to go then quickly bogs out, if you hold it there it will bog to the point of almost stalling. It also does this under load at 1/4 to half throttle when standing the bow up before plane.
The motor is from all accounts of a merc mechanic very healthy, compression is even across the board, some work was done to it. .20 over, new pistons... not sure what all.
Last night when on the water it completely died when sitting with bow up. I had 4 people in the boat so it was having to work to get on plane. it wouldn't easily start afterwards until the fuel was primed again.. Upon inspection after we pulled it out of the water, i removed the intake cover and there was some raw gas at the bottom and all over the front of the motor.
I am not sure if it is running too rich, or not getting enough fuel from the tank at wot or under load, or what the issue may be. Any suggestion on where to start or what to do to more difinitively determine the problem would be much appreciated. Thank you very much for taking the time to read this.
Vince

Re: 200hp Mercury Black Max Bog

Posted: Jun 08, 2012 2:27 pm
by 77viper
pull the fuel line from the boat to the motor and remove the end to look at the inside of the line itself. The merc gray line with the red writing on it will come apart on the inside causing a fuel restriction.

If that looks good try pushing the choke as it's acting up.