90 Marathon just quit while driving

[2907blue]

My old reliable 2 cycle Marathon just quit like it ran out of gas. It was low on gas, but had some in it. Oil tank half full. I added gas and cranked for a while with no luck. Tried starter spray to see if I had a gas problem and got nothing. I then checked spark and saw none. The odd thing to me is that it started and ran fine 2 minutes before and then died, which it never does. What would cause the instant loss of spark - ignitor, coil failure? How do I troubleshoot each of those before plunking down almost $100 each with trial and error? I'm new to this forum and am thankful I found it! I appreciate any help given.

thanks

[popatop]

Hi 2907blue, I would check all the grounds and make sure they are good first

[Dave Box]

Popatop is correct. You should remove the ground cable to the frame and clean everything to bare metal. Also make sure that the cable from the ground point to the engine is intact. If that has corroded or broken the engine will try to ground through anything it can with very strange results.
Now with a voltmeter check that with the switch on and the throttle depressed you have 12 volts on the coil. (Caution the engine will crank and may start so you should put it on stands or remove the drive belt).
Once that has checked out remove each connection (one at a time) on the coil and the ignitor and check for corrosion. You may also find that the wire has snapped right on the crimp and is being held together but the rubber sleeve so give each wire a gentle tug.
Having eliminated a wiring issue and if the car still does not run we need to check the ignition. The first step is the pulsar, so undo the connection and measure for ohms across the red and blue wire. You should see 75 to 140 ohms. Also check each wire to ground, you should see infinity. If that is good connect back across the red and blue and set your meter to ac volts. Now crank the engine and look for about half a volt ac.
If you do all that and report back we can move on.
Good Luck
Dave

[2907blue]

Thanks for the response Dave. I'll try your tips and report back.

[2907blue]

Found it!
It was a broken wire from the ignitor. Soldered in a repair and it started right up!

I appreciate the great suggestions from Popatop and Dave.

Thanks - this is a great resource.

[Dave Box]

Gotta love a story with a happy ending.