1987 force 50hp running rough

[bwentz]

Hey guys, my force outboard has been giving me some trouble lately. It starts up fine, but it runs rough and shakes while at idle. If a wait a minute, the RPM jumps almost like the second cylinder just started to fire, but after 10 sec, its running the way it was when I started it. I think it could be the cdi box, but I replaced the cdi 2 years ago, and the other cdi is the original since 1987 is working fine. Also, I notice the bad cylinder, or so I think, the plug is not burning chocolate, it white. Can anyone help me? Thanks.

 

[slag]

Re: 1987 force 50hp running rough

White is lean, very lean. Sounds almost like there is an obstruction in your fuel system if the ceramic tip is white.

 

[foodfisher]

Re: 1987 force 50hp running rough

"White is lean" or water intrusion.

 

[bwentz]

Re: 1987 force 50hp running rough

I just replaced the head gasket and fuel pump diaphragm not to long ago and it didn't seem to make any difference. where else can water be getting in?

 

[procraftguy]

Re: 1987 force 50hp running rough

When u have the jump in rpms apply light presure to the throttle at carb to see if its not returning to same spot the arm my be bent making it not return all the way every time ...just a thought