New Yamaha Owner needs some help!

[metricyamaha]

I got a pontoon with 2004 50HP Yamaha 2-stroke. It was running okay for a while, but then the spark plug boot got loose. This caused the ignition coil to fail. I replaced the ignition coil, and checked the timing; all looked okay for a day. Then it started to misfire on 2 cylinders. I checked the timing some other things again, and this time the timing was way off, so the linkage connecting to the CDI unit was actually 1/2" too short to set the timing on the TDC. (Top dead center of the piston)

Is there any way I can make sure that the CDI went bad? I don't want to spend $500 on a new one if I'm not so sure...

[99yam40]

What does DTC stand for?

I would measure the inputs and outputs of CDI with the proper meter and make sure all voltages are in spec like service manual states

[metricyamaha]

What does DTC stand for?

I would measure the inputs and outputs of CDI with the proper meter and make sure all voltages are in spec like service manual states

Sorry for the mix-up, I really meant to ask if the CDI was going bad or not.

I'll check the voltages tomorrow (hopefully). The service manual doesn't say if the voltages are DC or AC. I'm thinking that it's AC but I'm not so sure.

Thank you for your response,
Metric

[99yam40]

It is DC but you need a peak reading voltmeter made for these outboard motor ignition systems or a DVA adapter with a normal one.
even the Fluke with peak hold will not get it done

[metricyamaha]

Thank you for your answer!

I do have an analog multimeter, and I have a cheap digital multimeter with a "peak" button. I'm going to build the DVA adapter, but unfortunately I have to order parts online.

In the meantime, I checked the timing again. I have the CDI model with linkage advanced timing, which connected to the throttle cable. Right now, with the timing light, I cannot see the marks on the flywheel when the engine is idling. When I disconnect the linkage advanced timing and move the arrow about 1/2 way up (on idle) the engine smoothes out, and I can now see the marks on the flywheel. It is still misfiring.

My old timing light died, and I got a new one from Harbour Freight. It only lasted one day. I was ready to check the voltage CDI, but the service manual says to check the 'in' voltage and 'out' voltage, but it doesn't say on which wires. On top of that, the colors don't match.

Any advice, please?
-Metric