Tohatsu M40C ignition testing

I have the service manual and am performing tests as per the flow chart specifically looking at the exciter and pulser coils. Both coils test out fine for resistance but I can get no DVA readings for either coil. Pulser is new. I checked myself and I am connected to the terminals as specified in the manual. I have never tested for DVA before. Is there a common way that newbies screw up?

The engine starts but sounds rough at idle and misses badly at around 1/4 throttle. I am convinced that the coils are supplying voltage of some sort or I dont think the engine would start.

Any help is much appreciated.

Greg

I should add that i am looking for the reading while cranking the engine with the electric start.

The DVA is essentially a pulse latcher or stretcher. Allows you to see the voltage at the peak of the pulse on the analog meter. No special tricks to use a meter that way. Are you accidentally trying to read voltage while the kill switch is engaged? Common mistake. Do you have resistance and DVA readings at the ignition coil as well?

If the exciter and pulser coils checked out OK with a good ohmmeter, they are likely OK, BTW.

I dont know how to check the ignition or CD coils. My CDI unit whic is CD and Ignition housed in one sealed box together. I tested through spark plug leads to ground which should be secondary coils that were in spec. I am not sure how to check the primary coil or if my secondary coil check was valid. I also dont know how to test the CD unit seperately. If either is bad I would have to replace with the newer seperate components and a mounting plate.

Essentially I am trying to eliminate the ignition system as a source of problems and/or replace faulty components prior to moving on to other systems.

Thanks,

Greg

My service manual assumes that my CD and ignition units are seperate and only provides testing details for seperate units.

Kill switch is not engaged. Everything is hooked up as normal save disconnection of 3 wire harness between magneto coils and CDI unit. The tester leads are then connected to the appropriate terminals on the magneto side.

Greg

Sounds like you have something other than the CD module and ignition coil for a 40C. The Tohatsu parts originally were a siamese ignition coil (with both plug wires), and a separate CD module, charged by the exciter coil, fired by the trigger coil.

BTW, slow-speed problems are more likely to be caused by fuel system problems than CD ignition.

You need to get the correct service manual and the old style CD is still available so you would not need to convert anything.

Yeah I think its capacative discharge and ignition coil in one. The concept is till the same though I think. Charged by exciter and fired by trigger/pulser. I am thinking my testing meter may have a problem as I get get no DVA readings from exciter or pulser on any scale.

In any event I guess I'll work on fuel system. Just would have liked to rule out ignition all together.

Guru my manual is for 1 & 2 cylinder outboards up to 40. If there is a more specific manual available where can I get a hold of one? I can post the numbers of the motor if that helps.

Greg