one bank firing

S

skinhead

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Sep 22, 2010
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I have a 1978 V6 Johnson 150xl right side bank not firing, replaced power pack.
Ohmed stator ohm out the same as the side that is firing. Does anyone have a clue? Do not know what else to ck. I ck spark plug they are clean. Grounded them one the block to see if firing no spark. The coil packs are not new but I don't think they would all go bad at the same time. Need help Thanks
 
H

Haffiman

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Dec 17, 2009
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2,454
Re: one bank firing

If one coil goes 'bad' in the way it shorts between output and input, it will kill the new pack at first crank.
Start by checking the new pack at the working side.
If ok, run an OUTPUT test (peak reading volt meter AC) on both stator and trigger.
If new PP is 'gone', ohm test the coils between output and in-put.
Powerpacks are normally killed due to bad ground or sparks (output) jumping wrong places. NGK "R" plugs may even be a reason.
 
jtexas

jtexas

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8,646
Re: one bank firing

most likely cause: shift interrupt switch is stuck open.

[agree with your reasoning on the coils, this is just a tip for future reference: a coil can be easily ruled out by swapping it to a known working cylinder]
 
H

Haffiman

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Re: one bank firing

jtexas said:
most likely cause: shift interrupt switch is stuck open.

]
Click to expand...

78 V6, looks like a cross.
When did they get a shift interrupt switch?

As for swapping coils, not a good idea if already killed one PP.
If measured first and found ok, then perhaps as a test.
 
S

skinhead

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Re: one bank firing

It does have ngk plugs . I will chng plugs first then swap pp and hope I did not fry
it. Thank you for the tips
 
H

Haffiman

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Re: one bank firing

skinhead said:
It does have ngk plugs . I will chng plugs first then swap pp and hope I did not fry
it. Thank you for the tips
Click to expand...


NGK may be OK, but not if the "R" types.
Check that the plug leads are properly clamped to the heads and well off the cowling latches. jumping sparks from lower leads to cowling latches are a common problem and may cause a PP failure.
 
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