1983 Johnson 90HP V4 Won't start/No Power

[beercan67]

Last week when I ran my motor in the driveway, I connected the wrong cables (positive to negative and negative to positive) without realizing it because I must've been in space. I turned the key and there was a pop and a puff of smoke. I turned off the key, switched the cables and turned the key. The motor fired right up and ran. I turned it off. Turned the key and it ran.

Today, the motor started but wouldn't turn over the two times I tried. When I tried a third time, there's no power at all. I checked and tested the fuse and it's fine.

Obviously I'm not the mechanically inclinded boater, so could someone tell me in layman's terms what could've happened?

 

[iwombat]

Re: 1983 Johnson 90HP V4 Won't start/No Power

First, you probably blew the rectifier, so now your battery isn't charging.

If you blew the rectifer out in a bad way, you can also damage ignition components and even drain the battery. Disconnect the rectifier, charge up the battery, and perform a spark check.

 

[beercan67]

Re: 1983 Johnson 90HP V4 Won't start/No Power

iwombat,

Before I wreck something else, is there a way I could get a diagram of the motor so I know what I'm looking at? I've looked online to find one, but couldn't. What's a rectifier and how do I do a spark check?

 

[iwombat]

Re: 1983 Johnson 90HP V4 Won't start/No Power

rectifier is a cylinder on a triangular base. It'll have some yellow wires coming out of it.

Do a search here on spark check, you'll get gobs of info.

 

[HighTrim]

Re: 1983 Johnson 90HP V4 Won't start/No Power

Is your tach no longer working? That is another sign that you blew the rectifier. Cross polarizing the battery will usually blow it in a hurry though. Do you have access to a multimeter, and am able to use it? There is a thread in the FAQ regarding testing your tach by Joe Reeves.

You can get an inline spark tester at about any auto parts store for under 10 bucks. Set the gap to 7/16 of an inch, remove all plugs, disable ignition, and ground out the spark plug leads to the block. Test one at a time. While cranking, the spark should jump the gap on all 4 cylinders with a bright blue ZAP!! You will probably need a helper for this if you do not have a remote starter.

Let us know what you find.