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No Spark on 5 HP 2 stroke

B

bcmbcm3

New member
Would appreciate some guidance from you folks about my motor. I read through dozens of posts and responses, but none had the information I need. This is a 1995 Tohatsu Model 369 M5B, serial #92616.

I have broken and cleaned all of the connections, and tested the lanyard safety switch. The salt water is tough on everything...

My research tells me to test the coil resistance next, but don't know the values. I found a great reference to share:
http://assets.fluke.com/appnotes/electricalpower/B0271b_u.pdf

While I "have you" - any advice about gently pulling the flywheel - I think this is where the points are located. It's been a long time since I have seen points, but I don't think they have changed much.

Thanks in advance! It is really cold here, and working on the outboard gets me thinking about summer...
 
I would highly recommend you get a Factory service manual, available from any dealer (including me), because you are way out in left field here. The M5B does not have/use points at all -- it has electronic ignition. The manual will give you the ohm specs you want. The coil tests are from primary lead to ground and from the plug lead to ground, BTW. The flywheel can be pulled with a "harmonic balancer puller" or "steering wheel puller" that uses 3 bolts, as long as they go in narrow enough to mate up with the 3 holes in the flywheel. Tohatsu America also sells an (expensive) puller designed for that job. As an alternative, you could remove the nut, gently load the wheel with a pry bar, and gently tap the end of the crankshaft with a mallet to "shock" it loose from the taper. Do not use a claw-type (3-arm) puller, or you may warp the flywheel.
 
The Factory service manual is Part # 003-21035-1 $42.47 Covers all 1 & 2 cylinder 2-stroke models.

If you don't have spark, you need to diagnose whether the pulser, exciter, cd, or coil has a fault, or whether you have a defective wire. You need a good analog ohmmeter, and a DVA-equipped voltmeter to take these readings. A digital ohmmeter will not give you correct readings.

If you want to work on the motor yourself, and expect to sell it soon, consider selling the manual with the motor. If the technology seems strange/confusing, perhaps having a dealer look at it would be easier/cheaper. YMMV.
 
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