Logo
FULL SITE MENU

Spark failure Classic 50

timguy

timguy

Silver Medal Contributor
Have a Merc 50 Classic. Spark dies when motor is run about 1 minute. It will restart after about 5 minute rest. After that no spark again unless you wait 15 min. It will only run for a few seconds but runs good, on all four cyl. Stator tests 1.5 thou ohms on low speed side, should be 7 thou or so, right? High speed side close to specs but 10 ohms down. Stator was replaced at one time but I don't have a good repair history. Switch box also replaced with a used one and looks like an aftermarket unit. Trigger tests fine. What do you think? I have a good used switch box but I'm hesitant to try it with the stator out of recommended parameters. Thanks, Tim
 
If you want a "second opinion" on the above advice (which would also be my advice), hook up your ohm meter again and then grab a blow dryer or heat gun and start warming up the flywheel.

If the resistance starts to climb that is a sure indication that you have cracked or otherwise unserviceable bobbins in the stator - the blow dryer/heat gun simulates the motor warming up while running, causing the copper windings to expand and lose continuity.
 
Neat trick!

Here's my stator tale of woe: Merc triple with ADI. Motor started lousy and would not idle down. Made poor power at idle and would stall going into gear. Stator checked out perfectly with ohm meter and DVA meter--but, it was junk. Put another on and all is well.

Jeff
 
I like your quote.....how true it is.
Stator is a CDI unit and I got impedence specks from them too as many of their products deviate from OEM specs. In this case they were about the same. I'm going to replace it with a good used Mercury stator that has no variance when heated up and specs are perfect right on. Worried however about the switch box and if anything ailing that unit could shorten the life of my replacement stator. Whats your experience on this.........?
 
If anyone cares, I replaced both units and the motor runs like a champ........at least for now! Gave the guy a quart of Amsoil 100:1.
 
we care...we always like to hear what fixed or didnt fix one we have worked on....thanks for the info...
 
Seems no charge, but the guy is going to bring it back after his family camping trip. He probably had no charge before as my stator met all tests. I was going to change out the rectifier but he had to go. Still owes money so I'm holding back too......first time customer. Its on a pontoon, trim and tilt......beautiful motor. Runs like a Swiss watch.
 
Back
Top