1990 Force 120, no spark (after just having been running)

[submariner1980]

Re: 1990 Force 120, no spark (after just having been running)

Oscilloscope is the best tool in electrical systems troubleshooting. Don't forget to take spark plugs out of cylinders and ground them before cranking with kill wires disconnected.

 

[jerryjerry05]

Re: 1990 Force 120, no spark (after just having been running)

I had that when I first bought my boat.
Went out and it ran great.
Then shut it down to fish.
Wouldn't start????
Sheared the flywheel key.
Check for TDC.

 

[khnitz]

Re: 1990 Force 120, no spark (after just having been running)

Interesting (sheared the flywheel key). The timing would be off, but it should still show spark, right?

I have a lot of things to try once I get back to the boat. To be honest, I may only have a chance here and there through the Winter. But, I'll be sure to post updates here. I really hate finding threads where someone posts a question, gets some good advice, but never posts back what their ultimate solution was...so, I'll be sure to chronicle my progress and post the final results here.

Thanks, again!

 

[jerryjerry05]

Re: 1990 Force 120, no spark (after just having been running)

You might get spark?
Maybe not.
When my motor stopped I'd get spark then not.
Look up under the flywheel and see if the magnetic strip is still in place and didn't come loose?

 

[khnitz]

Re: 1990 Force 120, no spark (after just having been running)

You might get spark?
Maybe not.
When my motor stopped I'd get spark then not.
Look up under the flywheel and see if the magnetic strip is still in place and didn't come loose?

Reviving this thread because, well, the snow has FINALLY melted and I'll start to have some time to get my boat running again.

One thing that just occurred to me: before the engine got to this point (while it was still running) the tachometer would drop out and not read from time to time - like, cruising along at 3500-4000RPM, and then no reading for 5 or 10 seconds, and then back to 3500-4000RPM .

I'll have to check my wiring diagrams when I get home this evening, but maybe this could help point out which component in the ignition/charging circuits has failed.

 

[SkiDad]

Re: 1990 Force 120, no spark (after just having been running)

this happened to me a few years ago - i had to replace the stator, which was easy enough to do with the help of the fine folks on this site. Got my stator for a good price at outboard ignition

 

[khnitz]

Re: 1990 Force 120, no spark (after just having been running)

this happened to me a few years ago - i had to replace the stator, which was easy enough to do with the help of the fine folks on this site. Got my stator for a good price at outboard ignition

Thanks for the BTDT help! I'll definitely start there when I get the flywheel off.

 

[SkiDad]

Re: 1990 Force 120, no spark (after just having been running)

get a tester if you don't have one and take a look at this doc to trouble shoot: http://www.outboardignition.com/support/176-3095.pdf

 

[Jiggz]

Re: 1990 Force 120, no spark (after just having been running)

The tach gets its signal straight from the stator and is connected on the source side of the rectifier. Since this is a very old thread, you need to post if you have done all the previous recommendations before pulling out the flywheel, i.e. disconnecting the kill wire from the terminal board inside the cowling, disconnecting the rectifier, and then verifying if you have sparks on all cylinders. Additionally, verify all bullet wiring connectors from the trigger and stator. Looking at them is not enough, instead you need to disconnect and reconnect including those under shrink wraps to make sure they are still good and not deteriorated.

 

[khnitz]

Re: 1990 Force 120, no spark (after just having been running)

The previous recommendations were covered in earlier posts (disconnecting kill wire, disconnecting the (now swimming) rectifier).

I checked wire-by-wire from the ignition switch to the engine for continuity of connections, but I will verify the individual wires/terminals at the engine, too - always good to do. I can reflow some solder to each crimp connection, too, for added security.

I have the parts to pull the flywheel to get a good look at the stator and the key, just need to get the time to continue the work. The continued discussion and help here is MUCH appreciated. Oh, and I'll be building a DVA to get accurate peak measurements from components I have lying around, too.