1982 70hp 3cyl Weak spark?

[smplesoft]

It appears the I am having a misfire. What should my spark look like on the plugs? These are NGK BUHW surface type plugs and I am seeing a very very small, thin, white spark. It appears weak on all 3 plugs but the weakest is cyl #1 and better on cyl #2 and even better on cyl #3 but all seem like they are not very strong. I read somewhere that mercs require a wide blue spark.

New Parts replaced so far....

Trigger (broken wire)
Stator (dry-rotted wires)
Rectifier (Shorted to ground. No tach)
Switch Box (No output to Coil #2 DVA)
New Plugs (NGK BUHW)

Please help. Anyone..
Kirk

 

[westexasrepublic]

Re: 1982 70hp 3cyl Weak spark?

I have the exact symptoms on my 79' 70 Mariner. I replaced all exsept plug wires and switch box. coils tested fine, have you tested your coils? Im currently trying to remmedy the problem with the timing.

I dont know about you but its giving the feeling like its a weak spark and my plugs are comming up fouled a bit and feels like its running rich. But my theory is that its just not firing at the right time causing weak combustion. once I set the timing, then ill make the move to replace the plug wires and switchbox.