40hp, No spark

[loganmenk]

Today was bitter sweet. I put in my parts to fix my trim that wasn't working, put the muffs on, went to start her for the first time in a few months and...... nothing. :facepalm:

I have no spark. It cranks fine and has fuel. The battery seems to be charged but I read on a post that it needs to be 100% to give any spark.. Is this true? I don't want to keep cranking and ruin anything expensive.


Motor: 1994 40hp 4cyl 2-stroke
S.N. 0G098660


Also, here is a picture of the boat so far.. She's coming along!

 

[carholme]

Re: 40hp, No spark

If you don't have the engine manual, here is one for you:

http://1manual.com/Mercury manuals/Service Manual PDFs/TwoStroke/814676r1/cover.pdf

You must have Adobe Acrobat reader installed to use this manual. If you scroll down to the lower part of the opening page, you will see the various engine components in red. Click on the one you want and when the first page opens, click on the "Save As" icon at the top LH corner of the page and you can save it to your computer.

There is a good beginning in the Ignition section re troubleshooting to get some of the basics out of the way.

Gerry

 

[1nebel0]

Re: 40hp, No spark

Pull yellow and black wire off the switch box to eliminate your key switch..use a remote starter to see if you have spark now...common problem and people go out and replace stator's, switche boxes and everything in between..this is the first thing I always do...They take off the yellow charging wires to eliminate the charging circuit...then you need to start testing everything else per Gerry above...good luck

 

[aussieflash]

Re: 40hp, No spark

Sounds silly but is your kill switch/lanyard activated?......ive done it.

 

[loganmenk]

Re: 40hp, No spark

Okay. I tried the tests and never saw a bit of voltage. This leads me to think something else is wrong. I haven't started the motor on my boat, but I heard it run really well on the previous owner's the day I bought it.

I never saw a kill switch, where would it be? Maybe I don't have one? The only wires I hooked up were the large connector under the hood.

 

[CharlieB]

Re: 40hp, No spark

The Ignition Switchbox on the motor has a BLACK wire with a thin Yellow trace on it, this is the 'ground-to-kill' wire, disconnect it from the engine wiring harness and retest for spark.

Remember there is a minimum cranking RPM of 300 for the stator to generate sufficient voltage to operate the ignition.

If still no spark, then DVA test the stator and triggers as outlines in the manual.

 

[loganmenk]

Re: 40hp, No spark

I only see a single post with 2 black and yellow wires. Is this the wires I disconnect?

 

[CharlieB]

Re: 40hp, No spark

One wire connects to the switchbox, one connects to an object about the size of a tube of lipstick which is the tilt kill switch.

Disconnect the Black w/yellow from the switchbox so that it is NOT connected to anything.

Now retest for spark.

A short in the ignition switch, wiring harness, tilt switch, ANYTHING that would ground the Black w/yellow will kill all spark.

This test will rule out all ground problems that would affect the ignition.

If still no spark, then you will need a DVA meter or DVA adaptor to further test the triggers and stator.

Remember, there is NO return on electrical parts, some are costly, test TWICE and PROVE the fault before ordering any parts.

 

[loganmenk]

Re: 40hp, No spark

It has started! Thanks everyone! So my next question is where do I hook up a kill switch?