No spark Yamaha V4 115hk

[YamahaUser]

Hello! I am having problems with my old Yamaha V4 115hk. There's no spark and i've been following the diagnostic steps presented in the service manual.

There seems to be a problem with both the CDI unit and the stator assembly;

1. No output at all from the CDI-unit. It should be 120 peak voltage.
2. The charge coil resistance is out of range, it should be 428-642 ohms (brown to red) but it's 1100ohms and it should be 48-72ohs (blue to black/red) but it is 120ohm

The peak voltage output from the charge coil is higher then specification, red to brown = 160 volts (reference value in manual is 130volts) and blue to black/red was also a lot higher but i can't remember the value at this point ..

My questions:
Should i replace the CDI-unit? It gives no output even though the charge coil give more then enough input
Should i also replace the stator assembly? The voltage output seem fine (or is it to high?)
Could the CDI-unit take damage from a faulty charge coil? Like to high voltage? What does the ohm-reading say?

[99yam40]

specs are for minimum peak voltage
over is fine.
you also need to measure the peak voltages from the pulser coils to CDI.
something has to tell the CDI when to fire the plugs
so you need to check all reading into and out of the CDI

hopefully you are using the correct voltmeter or a DVA adapter and regular meter set to the proper settings

also the kill switch(man overboard) grounds the voltage to keep the spark from happening,
did you check to make sure that switch or wiring is not your problem?

[YamahaUser]

Hello! Thank u for helping me

I have only measured the ohm values from the pulser coil and they were in range. But I will check the voltage also, to be sure it's OK. I have an multimeter that can measure peak max and min values, not just mean voltage.

I've already checked the killswitch and it is fine..

But the charge coils, the ohm readings are way out of range and i don't really know what that means? According to the manual i should change stator even though the voltage output seems fine?
The thermo switches. what happens if they are faulty?

[YamahaUser]

The previous owner said that the engine died at cruising speed.. it had to be towed to port. Later it started again, only once, but since then it is dead, no spark.

[99yam40]

peak voltages that you can compare to the spec in the manual need to be read with a meter designed for these Capacitance Discharge Ignition systems or get a DVA adapter to use you regular meter.
manual should also tell you to set the meter to DC v.
what brand and model is the meter you are using

may look to see what that kill switch wire is going into the CDI and try to disconnect it to make sure the wiring is not going to ground somewhere along its path to the CDI

[YamahaUser]

I have this model UNI-T UT161D

Yes, if i have the dva adapter i need dc v otherwise it should be ac v.
I have already tried by measuring the ignition and kill switch and it seems fine, i've also tried disconnecting the white wire which is the killswitch-wire.. :-)

The only problem i've encountered so far is the high ohm of the charge coil and the non-voltage output from the CDI-box

[boscoe99]

What year 115 motor? What is the complete engine ID? A 115HK is not a model offered in the USA.

[YamahaUser]

It's in europe I don't know the year because the identifcation sign is gone. But the other sign that tells serialnumber show 115 AE, 6E5 L (And then serialnumber which i can't rememeber at this moment). I guess that is mid to late 80's. Its metallic paint.
Today I did measure the pulser coils, which where fine, like 7-8 volts, above specs. I also again disconnected the kill-wire, the over-rev wire and later also the thermo switches. Still no spark

[99yam40]

if all CDI inputs are good and there is no output voltage with the kill wire ungrounded, then I would say it is a bad CDI

[boscoe99]

Has the white wire been tested at its entry point into the CDI box?

[YamahaUser]

Yes. It works fine, and also i tried to disconnect it just to be sure. Ordered a new CDi-box last night.

[YamahaUser]

Update: I have installed the new CDI-box which solved the problem. The engine now starts and runs It wont idle though, dies after a short while. Lot's of smoke. works fine at higher rpms. Could maybe a carburerator cleaning and tuning fix this problem?

[99yam40]

Update: I have installed the new CDI-box which solved the problem. The engine now starts and runs It wont idle though, dies after a short while. Lot's of smoke. works fine at higher rpms. Could maybe a carburerator cleaning and tuning fix this problem?

possibly, yes

Might want to make sure to follow the link and sync procedure
and make sure the timing is checked (which is part of that)
if oil injected, also make sure the linkage to that is set properly too

trying to start the motor with no spark probably dumped a bunch of fuel into the motor and will take a while to clear that all out of the crankcase.
pull and clean the plugs off and spin the motor over while they are out to help clear some of it out