How to Check Out CDI on 1997 Yamaha 80hp

[fishfun83]

Thank you 99yam40. I am going to do further investigations tomorrow to try to figure this thing out. The CDI, being a closed box with no terminals, makes it difficult to verify the proper voltage is coming from the various coils. May have to poke a pin into a wire.

Also, when I do a search on the internet for parts for the C80TLRV, in the magneto section, there is no lighting coil identified. Perhaps it is integral to the Charge Coil?

Thanks again for your help. Hopefully I can start narrowing down things tomorrow.

[99yam40]

never good to poke holes in insulation.
they make adapters to hook into the wiring harness so you can get to the connectors.


If you unplug the connectors you can do the unloaded test, but if you want to do the loaded testing with it all hooked up then you can back probe the connectors where the wires run up into the rubber plugs without damaging the wire insulation with small straight pins or paper clips being careful and hook meter up to them

[fishfun83]

Yes cpostis. That is the wiring diagram I have.

[fishfun83]

While looking over the manual this morning, I see this statement that is associated with the checking out of the CDI. Can it be true that Number 2 cylinder does not fire during cranking? Check out page 8-19 of the Yamaha Service Manual.

[99yam40]

Looks like you found where you problem is .

Take voltage tests while it is running now not cranking

[99yam40]

Yes cpostis. That is the wiring diagram I have.

Did you notice there is a lighting coil in that diagram

[cpostis]

Did you notice there is a lighting coil in that diagram

Yes, and if you look there is rectangular connecter from the pulsar coil that feeds into the CDI, a triangular connector from the charge coil that feeds into the CDI, and a rectangular connecter from the lighting coil that feeds into the rectifier/regulator. Take a look at your motor and confirm if you like.

I'm pretty sure you have a lighting coil!

[cpostis]

Yes, and if you look there is rectangular connecter from the pulsar coil that feeds into the CDI, a triangular connector from the charge coil that feeds into the CDI, and a rectangular connecter from the lighting coil that feeds into the rectifier/regulator. Take a look at your motor and confirm if you like.

I'm pretty sure you have a lighting coil!

[IMG]C80TLRV.Magneto by Charles Postis, on Flickr[/IMG]

Well, looking further your connections may be different than in the 2000 diagram I posted. Looks like the bullet connecters in this diagram are for your lighting coil. If this is right, you have a different stator assembly than in the 2000 diagram I sent.

Can you tell us exactly what connections you have, or post an image of the diagram you have in your manual?

Others, Boscoe, Rodbolt, Fairdeal, etc.? Can you review this thread and comment?

Thanks!!

[fishfun83]

This is the wiring diagram that I believe applies to the C80TLRV. I don't know how to make it larger.

[cpostis]

This is the wiring diagram that I believe applies to the C80TLRV. I don't know how to make it larger.

I was able to enlarge, but very fuzzy. 4,5 ,and 6 are lighting, charge, and pulsar coils respectively. Looks like in your diagram connecters are as in my 2000 wiring and your diagram and not like in the last Yamaha parts diagram I posted for your C80TLRV. (Yamaha Publications can and do have discrepancies)Next time you look at your motor, can you verify (rectangular connecter from the pulsar coil that feeds into the CDI, a triangular connector from the charge coil that feeds into the CDI, and a rectangular connecter from the lighting coil that feeds into the rectifier/regulator)?

As 99yam said, "lighting coil on Yamahas feed the RR to keep the battery up", has nothing to do with ignition.

If your CDI does not get the specified range of peak voltage from the coil(s), you're not going to get good spark. # 2, I don't know what coil feeds the CDI to get the required voltage. Back to checking peak voltage from coils with a DVA to confirm? From what I reviewed, if your CDI is not getting a signal from the CPS, it will not spark? I'm a bit confused and looking for someone on this forum to tell us?

Edited: I see Rodbolt answered this question in your other thread "that 1 pulsar coil controls spark on 1&3. 2 is made up in the CDI based on the CPS input."

So, if 1 and 3 are firing from pulsar coil, 2 should fire above 500RPM without cranking as well as long as you are getting a signal from the CPS to the CDI, the CDI is good, there are no opens/shorts in your wiring, your ignition coil for # 2 and spark plug wire and terminals are good.

[fishfun83]

[QUOTE=cpostis;128346]I was able to enlarge, but very fuzzy. 4,5 ,and 6 are lighting, charge, and pulsar coils respectively. Looks like in your diagram connecters are as in my 2000 wiring and your diagram and not like in the last Yamaha parts diagram I posted for your C80TLRV. (Yamaha Publications can and do have discrepancies)Next time you look at your motor, can you verify (rectangular connecter from the pulsar coil that feeds into the CDI, a triangular connector from the charge coil that feeds into the CDI, and a rectangular connecter from the lighting coil that feeds into the rectifier/regulator)?

As 99yam said, "lighting coil on Yamahas feed the RR to keep the battery up", has nothing to do with ignition.

If your CDI does not get the specified range of peak voltage from the coil(s), you're not going to get good spark. # 2, I don't know what coil feeds the CDI to get the required voltage. Back to checking peak voltage from coils with a DVA to confirm? From what I reviewed, if your CDI is not getting a signal from the CPS, it will not spark? I'm a bit confused and looking for someone on this forum to tell us?

Edited: I see Rodbolt answered this question in your other thread "that 1 pulsar coil controls spark on 1&3. 2 is made up in the CDI based on the CPS input."

So, if 1 and 3 are firing from pulsar coil, 2 should fire above 500RPM without cranking as well as long as you are getting a signal from the CPS to the CDI, the CDI is good, there are no opens/shorts in your wiring, your ignition coil for # 2 and spark plug wire and terminals are good.

Thanks for all the great information and I believe you are spot on. This afternoon, I disconnected several of the connectors including the signal connector to the number 2 cylinder, the CPS connector, the lighting connector and the main coil connector. I measured some resistances, pulled on wires to look for shorts and put all back together. Low and behold, number 2 was firing when I cranked up. Evidently, there is a short somewhere. I am going back and reinspect all the wires and connectors and spray some good aviation corrosion retardant spray inside all the connectors and hope for the best. Please let me know if there is something else I should so and I really appreciate all of your help.

[cpostis]

Great! Be sure to check/clean/tighten all ground connections as well.

I clean my connectors and terminals with LPS Electro Contact Cleaner, then coat with LPS 1 Greaseless Lubricant/Moisture Displacer.

[99yam40]

more than likely it was not a short, but a bad connection(high resistance) in one of the connectors

[pstephens46]

more than likely it was not a short, but a bad connection(high resistance) in one of the connectors

Yep. Shorts are usually more dramatic. Smoke and blown fuses...

[cpostis]

Yep. Shorts are usually more dramatic. Smoke and blown fuses...

Now, even though rarely occurs, an unwanted shunt (where the path of the electrical circuit goes other than where intended and does not short to ground, nor blow fuses and burn conductors or components) is another story.

Had this happen a few times with control circuits for building HVAC systems during my career.

Maybe we can discuss that?