80HP 2-Stroke Ignition Issues

[Nuclear-Inc]

Hello,

I have a Yamaha 80HP 2 stroke 1997 Model# C80TLRV. I have lost spark on cyl #2. I have done some research/testing, and ended up needing a new CDI. However I would just like to hear another opinion. I swapped coils, checked all connections, changed CPS, rebuilt carbs. I verified fuel flow. According to my research #2 spark is con*****ed by the CDI and CPS. While #1,3 are via the pulser coil. Engine starts fine fine, revs up no problem. This engine has very low hours, and is hard to believe the CDI went bad.

Any info would be appreciated.


Thanks,

[99yam40]

have you tested the CPS output or anything else, or just changing parts

[Nuclear-Inc]

have you tested the CPS output or anything else, or just changing parts

I found original CPS with a little corrosion but passed tests described in the maintenance manual. I went ahead and replaced it with a used CPS from a working engine in mint condition.

[TownsendsFJR1300]

Soooo, is it working NOW or still no spark (kinda vague) or I'm missing something?

.

[boscoe99]

What do the carburetors and fuel flow have to do with no spark?

[Nuclear-Inc]

I’m still without spark on #2.

[Nuclear-Inc]

What do the carburetors and fuel flow have to do with no spark?

I just wanted to point it out.

[Todd H.]

When you swapped coils I guess you swapped wires as well? I would get a copy of the CDI troubleshooting guide and a dva tester you can build or buy.

[Nuclear-Inc]

When you swapped coils I guess you swapped wires as well? I would get a copy of the CDI troubleshooting guide and a dva tester you can build or buy.

You cannot swap wires because they come from the CDI internally. I swapped coils assemblies completely.

[ausnoelm]

Interesting, you said you replaced the CDI, and still have no spark, yet ask why/how a CDI could fail so early, it didn't fail did it, or am I bamboozled by the descriptions?

[Nuclear-Inc]

Interesting, you said you replaced the CDI, and still have no spark, yet ask why/how a CDI could fail so early, it didn't fail did it, or am I bamboozled by the descriptions?

I'm still waiting to buy a new CDI. The engine still has it's original CDI installed. I have been shopping around, and found a used CDI for $300. However, I think it's better to just spend the $600 on a new CDI with a superseded PN.

[TownsendsFJR1300]

I'm still waiting to buy a new CDI. The engine still has it's original CDI installed. I have been shopping around, and found a used CDI for $300. However, I think it's better to just spend the $600 on a new CDI with a superseded PN.

Being a 24 year old motor (in the marine environment), I wouldn't doubt it has may have issues, even with low hours...

.

[99yam40]

making sure the peak voltage inputs to the CDI are all in spec, and then what the outputs of the CDI is always better than resistance readings , if that is what you have done

[ausnoelm]

Agree, test before replacing expensive parts.

[boscoe99]

making sure the peak voltage inputs to the CDI are all in spec, and then what the outputs of the CDI is always better than resistance readings , if that is what you have done

Do think that a CDI assembly can be tricked by using say a 90 volt battery to charge a capacitor and then using a magnet to trick the pulser coil into firing the spark plugs?