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86 90 hp mercury runs at full throttle dies when i throttle off

R

ruiz727

New member
im having problems with my motor i have no problem starting it but dies when i put it in reverse gear also at full throttle will run great as soon as i come off throttle back to idle it dies.i have replaced the fuel line,primer bulb,spark plugs,fuel tank,fuel filters,also cleaned out the 3 single barrel carbs. im at the point that the carbs are gonna have to be rebuilt any help thanks
 
Start with a compression test !!!-------It is the # 1 step to start with in your trouble shooting.--------------The carburetors must be clean , -----------I have cleaned many outboard carburetors , I can not ever recall rebuilding one and it is an " overstatement " and used a lot here.----Use a timing light to verify that it is running on all 6 cylinders , they will run on only 5 and that happens all the time.
 
thank you I really didn't think about a compression test,since the motor runs great at full throttle but at trolling speeds of 3 to 4 mph it dies wont stay running untill i give it more gas.i will check it out hopefully i dont have a dead cylinder
 
We see a lot of posts that say --------" Rebuilt the carburetors and my motor still runs the same "------------Which to me means that no trouble shooting was done.---------And it might be as simple as opening the low speed jets an 1/8 turn or bumping up the idle stop.
 
I have a 1985 johnson 185 v6,Motor will fire rite off and about a minute later it will start idling rough like its flooding out and die then will not start again.
 
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