Only one cyl firing in idle

[Chaney101]

is this normal for only my top cyl to fire in idle. I thought at leat 2 were supposed to. 2003 Merc 90 elpto 2 stroke. Thanks
P.S. Did this with timing light.

 

[Laddies]

Re: Only one cyl firing in idle

You have a CDM shorted, could be the ground circuit on #1 or the stop diode is bad on #1

 

[Chaney101]

Re: Only one cyl firing in idle

#1 being the top cylinder? Dont mean to sound dumb but that is the one that was firing. I pulled the wiring harness on the cdms and replaced them. Now all three are fine. Could this be causing my only getting to 4000 rpm problem? I thought carbs, but it ran perfect the week before. Can carbs gum up that quick?

 

[Laddies]

Re: Only one cyl firing in idle

You said you didn't have fire on 2 & 3 and I gave you the anwser for no spark on those 2 cyls!