Johnson 30 only 1 cylinder fires

[Gary1]

Alright where to start, seems to be alot of problems with this.

1.The lower cylinder dosent fire, i checked the coil, plugs, compression, and plug wires, they are good. This cylinder will fire randomly when i am driving the boat. Ushually for about 3 to 4 seconds then cuts back out, but once in a while it will run until i turn the boat off, never fires when i start the boat always takes atleast a half hour.

2. Tachometer dosent read right. says it idles @ 500. Full throttle @ 1000. and when the 2nd cylinder does fire the tach instantly drops to 0 rpms.

3. Does not like to sit and idle, will idle for 15 to 20 seconds tops then stalls out. Seems to be getting progressively worse when restarting, getting harder each time.

I dont know much about outboards so any advice will be helpful.

Thanks Gary

 

[petryshyn]

Re: Johnson 30 only 1 cylinder fires

A little more info on year and model would be nice. Try disconnecting the yellow wires from the rectifier and see how it runs. A shorting rectifier and/or stator can cause ignition drop outs.

 

[tashasdaddy]

Re: Johnson 30 only 1 cylinder fires

http://forums.iboats.com/showthread.php?t=250879

 

[Gary1]

Re: Johnson 30 only 1 cylinder fires

Here we go its a 1996 30 hp Johnson w/electric start, 20 inch shaft. Hope that helps.
Also tried disconnecting the yellow wires (there were 3 of them so I disconnected them all) and it made no difference, only thing it changed was the tach read zero the whole time.

Also I tried swapping the 2 power (think they were brown) wires going to the coils, and it would not start when i did that.
Gary

 

[petryshyn]

Re: Johnson 30 only 1 cylinder fires

"Also I tried swapping the 2 power (think they were brown) wires going to the coils, and it would not start when i did that.
Gary"



it won't start because you affected the timing in doing so. Swap the coils instead and see if the misfire follows the coil to the other cylinder.

 

[Gary1]

Re: Johnson 30 only 1 cylinder fires

Swapped the coils, made no difference, both coils will fire the top cylinder, still no fire on bottom cylinder.

 

[petryshyn]

Re: Johnson 30 only 1 cylinder fires

sounds like a CD pack, timer coil or associated wiring.

Do a search on ignition trouble shooting