1987 DT20 No spark

[TheRebel]

Hello! New member here with a problem. Father/son project has gotten above my knowledge level. We recently purchased a small fishing boat with a, what I believe is, 1987 Suzuki DT20. Had spark at first and started but pretty rough. So we shut it down, replaced the plugs, fuel filter, cleaned the carb and put it back together. Now no spark to either plug. So we replaced the ignition coil which was pretty discolored along with the ignition sensor which looked the same. Still no spark. That was the end of my expertise and to the interweb I went which led me here. Any ideas what might be our problem? I appreciate the insight. Thank you!

[Hoosmatroos]

The lanyard switch? You can try to disconnect it first

[Solarman]

Does your motor have a key switch, or stop and start buttons?
Might be good to check each to see if working properly.
You mentioned an ignition sensor? Did you mean ignition coil under the flywheel?

Post back when able. Good luck.

[TheRebel]

Hello, thanks for the responses. It does have the lanyard kill switch which is still connected. How would one disconnect it? Just cut the wires or should I follow it back and disconnect it somewhere else? And yes I mentioned the ignition sensor as well as the ignition coil. We replaced both because they were pretty discolored, almost look a little burnt? I should probably get a service manual for the motor. I looked online for a free one, but no luck. Thanks again for the help guys, my son is itching to get on the water, which means bugging the crap out of me.

[Solarman]

The lanyard should have connectors. Disconnect, test switch with ohm meter, if good reconnect. Check any other plug connectors for corrosion, loose, dirty.

Post a pic of the serial number plate if able, want to make sure what parts are on your motor.

Post back when able.

[TheRebel]

Well I disconnected the lanyard, but didn't test it with an ohm meter yet. Still no spark. Here's a picture of the serial number plate.

[Solarman]

Your motor appears to be a 1988 motor. That's the year the second set of numbers started with 80....

I don't see the ignition sensor, that you replaced? I see a spark plug coil (also called the CDI unit), and an ignition coil in the magneto. I found it, right between the lighting coil and ignition coil, it is #8.

That ignition sensor needs to be close enough to the flywheel to pick up the magnetic impulse created when the flywheel magnet passes by as it turns. If too far away it may be too weak/not enough change to signal the CDI unit to fire.

Likewise, that stop switch/ lanyard, if not working correctly, could be grounding out the CDI signal, not letting it fire.

I would check the stop switch first, one side (2 wires) goes to ground, the other side to CDI. Check continuity to ground on the wire from lanyard to CDI unit. If total continuity to ground and lanyard is properly in place, then that switch may be bad. While stop switch is unplugged, check to see if you have spark? If so, replace stop switch.

If still no spark, stop switch may be fine. Then check ignition sensor distance to flywheel.

Good luck, post back when able to let us know how it went.

[TheRebel]

Thanks Solar for the reply. The sensor doesn't have much, if any, adjustment. Just two screws holding it to the stator assembly. I'll dig into the wiring for the lanyard this weekend. I did check to see if there was spark after I unhooked it and nothing. Time to get out the ohm meter and check connections. I report back my findings with some pictures. Thanks again.

[TheRebel]

It's been a while on this one as life has a way of getting busy especially in the summer. Went through the whole motor with an ohm meter and found out that it's the CDI that is bad. Getting readings on one spark plug wire but nothing on the other. Checking the parts diagram it shows I need a 32900-96340, found a few online but man they ain't cheap. Any alternatives that would work with this motor? If not I'll probably have to bite the bullet. Thanks again.

[TheRebel]

Just wanted to give this thread closure. Ended up selling the engine and getting another one. Too much work left on this one and best to let it go to someone who has more time. Thanks to those who replied. Your insight was very appreciated.