1997 C25 Ignition Question

[Clodhopper]

I have a 1997 C25 MLH. I have the factory service manual. I have cleaned and rebuilt the carb. New plugs. Been decarbonized. Clean fuel at proper mix.

I have a miss from low idle (1100 per manual) through roughly 2500, then it smoothes out through WOT

I cannot get the timing in specification using a timing light. Full retarded timing is 6 ATDC +-2. If I have the bracket adjusted all the way to retard, it won't go below 4. I know that is within the lowest spec tolerance, but then I cannot get 22BTDC WOT spec.

I have tested the pulser coil, charge coil, and primary and secondary coil resistance. All are outside of what the factory manual specifies. I verified the resistance readings with two different DMM's

I find it hard to believe that every part of my ignition system is bad. I have not tested the CDI box yet.

Also, the manual shows two pulsers and two ignition coils, I only have one of each, so is there a possibility the factory manual is wrong? Did they change something mid year?

Thanks for your help!

[boscoe99]

Not unusual for a Yamaha SM to have errors.

What are the values that you recorded for the ignition system components? Resistance and voltage please.

[Clodhopper]

Coil primary resistance is .3 ohms. Manual specs .18 - .24 Secondary side of coil- It starts reading and then climbs beyond the scale.

Pulser coil is 106.6 ohms. Manual specs 311 - 381

Charge coil is 240 ohms. Manual specs 342-418

My manual does not have voltage specs, and I do not have a DVA.

Edited to show manual specs.

[Clodhopper]

I have tested spark gap and it is hot blue at a 10mm gap

[99yam40]

I have a feeling you do not have a Yamaha service manual, maybe an after market one, but I could be wrong.

peak voltage is the best way to test, but since you show good spark, what are you concerned about?
I have no idea what manual would call for 1100 at low idle
did you verify the timing mark at TDC for #1 cylinder?

[Clodhopper]

I built a DVA. These are my voltage readings at idle

Charge coil 248 vdc
pulser coil 25 vdc

When I get this corrected, I will post the solution, so that maybe it will help someone else searching this problem.

[panasonic]

Go to http://www.cdielectronics.com/ and look up your engine...it should have the peak voltages you are looking for.