Mercury BlackMax 200Hp Stalling

[JoeBlow]

Hi I have a 1982 Mercury BlackMax 200 Hp that stalls sometimes after prolonged idling or running at slow speeds (Trolling Speeds). When it stalls it becomes difficult to restart sometimes I have to let it sit for 10 minutes. Once I let it run under load for awhile it runs good again. Any advice would be great.

 

[12Footer]

Re: Mercury BlackMax 200Hp Stalling

It may be overheating.

 

[JoeBlow]

Re: Mercury BlackMax 200Hp Stalling

If it was overheating wouldn't it run worse under load. Also the waterflow is still good and the water pump impellar is in excellent condition.

 

[BIGKASH]

Re: Mercury BlackMax 200Hp Stalling

plugs are fouled ?

 

[Reel Appeal]

Re: Mercury BlackMax 200Hp Stalling

Joe,<br /> Your motor is most likely "loading up".This is not un-common with the 80's V-6 Merc's.Make sure your gas/oil mixture is correct,measure accurately for 50:1 ratio.Check thermostats for proper operation.Any motor must reach it's optimum operating temperature to run effeciently.You may want to change the plugs if you have not done so in a couple seasons.NGK BU8H(surface gap).Clean out carbs. and bowls.Check needle valves/seats for wear.Try using 89 octane(or higher) fuel.<br />If all else fails,try installing NGK BU10H sparkplugs.

 

[JoeBlow]

Re: Mercury BlackMax 200Hp Stalling

Thanks for the advice, I will let you know how it goes.