90 HP Idles real rough

[laser51]

1999 very low hours oil injected 90 HP Mercury. Idles very rough and smokes, however when you give it more throttle it seems to run smooth and stops smoking.I have changed plugs and the fuel filter - no change.

 

[Laddies]

Re: 90 HP Idles real rough

It sound like the idle jets are set to rich

 

[DHPMARINE]

Re: 90 HP Idles real rough

laser51,<br />rough idle and smoke/okay after more throttle .... <br />sorry I'm thinking online.....<br /><br />So no stalling ? No hesitating ?<br /><br />Pull off your motor cover and find the carbs.Now look at the portside of the carbs.Near the top of each carb is a brass colored mixture screw.See how many carbs have these screws with springs under them.<br /><br />If all 3 have springs on this mixture screw you should be able to attain a decent idle.If only one or two carbs have these springs,you idle only on those carbs.<br /><br />This will explain a somewhat 'minor' rough idle,and a somewhat exicting wake to headway acceleration.Depending on the boat.<br /><br />DHP