20hp Suzuki problems? CDI?

[ASUAviator]

Hey all Ive had an issue with my DT20(1982) for a while now but have a 15hp Johnson as a back up. (man is there a huge power difference between these 2 motors tho). It started when it randomly didnt want to fire. Usually when I was starting it for the first time that day. It wasnt getting spark and progressively got worse. I found a way to play with the kill switch causing it to pop and sometime get started. It wasnt the real fix and the problem remained after I properly disconnected the kill switch. So I started to think CDI.

So tonight after it had been sitting a long while I decided to go through all the connections and see what I could get to happen. Pulled everything apart, cleaned them, put it back together, and hit the starter. Still no spark. So I decided to put a blow drier on the cdi for a bit since this didnt happen when it was warm. Hit the starter and I had spark! So do you guys think its safe to say its the cdi?? The rectifier sits right next to it so could it maybe be that? Is this a known way to test if the cdi is bad?

Wish I coud get it going again, it jetted my tinny around the lake. Too bad its a $300 dollar if I can find it. Thanks for any input

 

[ASUAviator]

Ill ask a more simple question. Once the CDI goes out, is it out for good?

 

[coreyltexas]

I recently had the same problem I bought a manual which you should do if you havent yet. It will give you invaluable information on how to diagnose most of the problems you will encounter. I downloaded a copy and print it out as I need it or just bring my laptop out to my boat to work. I found a copy online and downloaded the pdf version for only $5, and I have already put it to work for me by doing all the repairs myself.

That being said I would check each coil for spark first.

(1) Pull out your spark plugs and check for weak or no spark, take them out one by one and put them back in the plug but not in the motor, carefully hold them by the insulated wire and put them close to the motor to see if you get any spark. Or you can get a cheap ignition tester or loan one from AutoZone, Oriely, or NAPA for free.

(2) If you do get spark from that cylinder you know its not the coil. if the other doesnt spark connect that coil inline where the working coil was this will then be a problem with your CDI.

(3) I'm not sure with your Suzuki but on Johnson's they are a sealed unit and you cannot service them only replace.

This is what worked for me.

What is the model number on your Suzuki? It should be on a tag on the port side. I will try to help if I can not to promote a company on here but I have found marineengine.com to be the cheapest resource to find parts, and they have great exploded veiws of youe engine.

Sorry I cant answer your exact answer but I hope this sort of helps.

Corey

 

[ASUAviator]

Thank you for your insight. What I really need to do is get the manuals like you say. I know motors fairly well but this one has been stumping me. Sometimes it will spark, others it wont. so im having difficulty determining what its going out. Im sure its not the 2 kills switches but some other electrical. Oh well. Hopefully I can find a manual for the DT20 but past attempts have failed