Cylinder not firing

[oceanpearl]

Motor - 1997 Evinrude 175 HP V6

Hello all,
I changed the spark plugs in the motor and when i take the spark plugs out all of them but top right plugs are blackened. The one in the top right looks like it is a brand new plug and i can only assume that the cylinder is not firing which would cause the plug to look this way. Other problems i have is... The motor has trouble starting, the motor dies at idle, and during low rpm 1500-2500 cruising you can really feel it missing. However during high rpm cruising 3000-4000 i don't really notice it.

Any ideas on what could be causing this or things i should change?

 

[seasnake]

What about the Spark plug wires . There should be voltage at the end of the wire that fires the spark plug .

 

[oceanpearl]

So... turn the battery on and stick a volt meter into that plug and see if there is any voltage coming out of it?

 

[sfc2113]

you wont be able to check voltage at that wire, pick up a spark tester from you local auto parts, remove the wire and plug in the spark tester onto the wire. start the engine if you see sparks in the tester it working, if not is is a bad coil or may be failing under a load. So, you will need to test the cd coil. you will need to test resistance on the cd coil connected to the top right cly spark plug.
Remove the suspect coil to do these tests with accurate results.
Assuming you know ho to do a resistance test: If not , here:
http://www.youtube.com/watch?v=BXHu6y94V60

ohms from cd coil ground to engine ground should be 0.1 +or- 0.05,

Ohms accross from primary terminal to spark plug terminal should be 257ohms +or- 50 ohms.

also test the spark plug cable continuity, should be 0 ohms end to end.

 

[freddy063]

Had Had a similar trouble with my boat a few years ago, Yamahas, but they have the same basic components I went to the auto parts store and picked up a spark tester, there are two types, one that you just hold over the wire and look for the little light, which shows the brighter the light the stronger the spark. The next type connects right over the spark plug and shows the light if it working but also tests your end connector that pops over the spare plug. I found that one of my coil packs had gone bad, but in doing so I found that a few others had dirty connections that needed cleaning up. You can move the coil packs around to test if that’s the trouble.

 

[oceanpearl]

Replaced the spark plug wires and the motor fires up first time. I am going to test it on the water hopefully this weekend to make sure its running correctly and not missing when in motion.

Thanks !