'92 Johnson 140 won't start - no spark? power shortage?

[TxHorns]

I just tried taking my boat out this morning and one of the motors wouldn't start and has me pretty worried. It is a 1992 Johnson 140hp outboard.

What happens: when the pinion from the starter motor pops up to engage the flywheel (right name?) and start it turning, it will only turn the flywheel about 1/2", and then they both stop. It almost feels like there isn't enough power to crank it, but I charged the batteries and swapped them and either battery will start the other motor just fine. I tried swapping the starters between the two motors and both work just fine. Was afraid it was frozen, but I took out all of the sparkplugs and turned the key and the starter and flywheel spin normally.

Does anybody have any ideas of what it could be and how I could diagnose it? Let me know if there is any more information I can give that would be helpful. Thanks in advance.

 

[basspirate]

Re: '92 Johnson 140 won't start - no spark? power shortage?

check and clean all your connections. sounds like you have a dirty ground

 

[TxHorns]

Re: '92 Johnson 140 won't start - no spark? power shortage?

Thanks, one question on that though - when I removed and reinstalled the starter motor and the batteries this afternoon, I would think that messing with the connections then would have fixed that problem (and nothing looked dirty). Is there some other connection besides the batteries and the starter motor that could be the problem?

 

[basspirate]

Re: '92 Johnson 140 won't start - no spark? power shortage?

check the connections on the starter solenoid. they may be dirty or loose. you also may have a bad solenoid try swapping them. trace the ground (black wire) from the battery. it should be bolted to the block somewhere. on my engine it is. clean it and tighten it. i think there is a possibility it could be your key switch also. i dont know if your two engines have 2 seperate control boxes but you could try switching the main harness going into the engine to test the key switch.

 

[TxHorns]

Re: '92 Johnson 140 won't start - no spark? power shortage?

Thanks basspirate, going to head down there now and give this a try. will keep you posted.

 

[TxHorns]

Re: '92 Johnson 140 won't start - no spark? power shortage?

well, connections looked good so took it a shop and with a very quick diagnosis he concluded that there was water in my fuel and there was some corrosion in my cylinders now and the starter isn't strong enough to turn it over given that. The way he said it made sense. It hadn't been sitting more than a week so he THINKS it can be cleaned out... I am going to be in some real trouble if he's wrong.

 

[basspirate]

Re: '92 Johnson 140 won't start - no spark? power shortage?

sounds a little strange especially since you could turn the engine by hand but i guess anything is possible

 

[ezeke]

Re: '92 Johnson 140 won't start - no spark? power shortage?

More likely that your battery cables are due for replacement. They corrode inside the sheathing, especially where they bend a lot.

You do have full-sized water separating fuel filters?