Johnson 88 weak spark but runs very good

[surrender]

Johnson 88 weak spark but runs very good. At lest one cylinder getting weak spark. Connection between power pack and coil got wet in the past(before we got boat) because they show some rust and corrosion. Have cleaned them up but will probably get new mini coil boots and the connectors that go inside to see if that helps. In the mean time I am going to try to trouble shoot and check powerpack and stator with CDI instructions. Any tips? Boat has a miss in the mid range rpms. Tach dead so dont know rpms of miss but it is not at the exact same rpm everytime. Waiting on new tach

 

[tashasdaddy]

Re: Johnson 88 weak spark but runs very good

swap the coil completely to another cylinder, see if the problem follows the coil.

what year 88 is it.

 

[surrender]

Re: Johnson 88 weak spark but runs very good

Will do. They all seem to have a weak spark, one is much weaker than the rest, could not get the spark to jump more the 1/4-3/8" on spark tester. It whiteish blue I think but very thin and weak looking

 

[emdsapmgr]

Re: Johnson 88 weak spark but runs very good

An inductive timing light is helpful-it will show weak spark or misfires when the engine is running.

 

[ezeke]

Re: Johnson 88 weak spark but runs very good

If there is any sign of deforming of the ignition coil it should be replaced (including swelling, discoloring, cracking, or melting of the potting). Failing ignition coils can destroy a powerpack.

Weak spark can sometimes be attributed to the use of automobile spark plug wire, or to cracked insulators on the spark plugs. More often, it is due to grounding issues.