No fire cyl 1 yamaha 90 1985

[rbourge99]

Cyl 2 and 3 are ok no fire on 1. Rpld coil with known good coil, still no fire?

 

[99yam40]

check the pulser coil out put

 

[rbourge99]

Thanks for the response 99yam 40, 11.2volts cranking at 600 rpm through the dva

 

[99yam40]

Ok lets go a little deeper.
how many pulser coils are there on your motor?
My C40 has 3 , one for each cylinder
not sure what yours has.
Is that voltage in spec for your motor?
is that voltage the same for the other pulser coils?

 

[rbourge99]

My 90 only has 1 pulser coil. My Yamaha shop manual does not state a voltage range, only diagnostic testing with their digital meters... I have read that the pulser fires two of the cylinders directly and synthesizes the fireing of the third cylinder in this forum, not in my shop manual.

 

[99yam40]

your motor should have 2 triggers/pulser coils
I am fairly sure #2 is generated by CDI,
#1 and #3 use the triggers/pulsers,

Noticed that this chart says the 85 90 has 4 cylinders, so not sure what to believe

here is a link to CDI electronic throubleshooting guide page 167 starts yamaha info
https://issuu.com/cdielectronics/doc...ition_troubles

 

[rbourge99]

Found the problem, Yamaha shop manual I have is the wrong year for my motor and the tests I have done were wrong... The two pulser coils put out 6.2 volts on the dva. After replacing the cpi I now have good fire on all 3 cylinders. Now I must clean the carbs, for this motor has been sitting up for 5 years. Any thoughts?

 

[99yam40]

I always have thoughts. everyone does.

what were the DVA readings out of the CDI loaded and unloaded on all 3 cylinders?

strange to hear the output of just #1 was bad