90 won't fire

[raymondridge]

I have a Merc 90 in line 6, about a 1980, that won't fire on any cylinder. It has a good hot battery and it turns over fine, but no spark. Can you give a few things to check. Thanks a lot.

 

[Plainsman]

Re: 90 won't fire

Raymond,<br /><br />If you do a search for erickems, you will find out how to check the switchbox. The guys here are a great help!<br /><br />What is the serial #?

 

[raymondridge]

Re: 90 won't fire

The serial # tag has a big scratch through it and I can't read it. It does have a tag that says 1979 1/2 M90 on it. Thanks

 

[Plainsman]

Re: 90 won't fire

On my 76 115, the serial # is also stamped on the starboard side near the back of the engine itself.

 

[raymondridge]

Re: 90 won't fire

How about 87872.

 

[Plainsman]

Re: 90 won't fire

It should be 7 digits

 

[raymondridge]

Re: 90 won't fire

I can't come up with it. All I know, is that it is a 1979 inline 6. Can I get some general things to check? Thanks

 

[Laddies]

Re: 90 won't fire

Start by disconnecting the blk/yellow wire from both switch boxes and ck for fire that will tell you if the problem is on the engine or wiring if you still have no spark and have excess to a OHM meter or DVA we can give you specs, for either one let us know.