Yamaha C115TXRS No start, no spark- intermittant

Popster

Seaman Apprentice
Joined
Jul 18, 2007
Messages
44
My C115TXRS has suddendly stopped starting. After sitting for a week (usually used 4-5 times a week) it was hard to start. Usually, I just choke it and give a little acceleration via the idle lever and it starts instantly.

After priming the fuel bulb, etc, the motor started after a couple of minutes. Lots of smoke due to trying to start it It ran perfectly after that and started instantly.

Today, after a two day rest, I went to go crabbing and the motor would not start. I verified the following:

Good gas in tank.
No water etc. in spin on filter or in motor filter
Starter works
NO SPARK!
fuse good
Pulled white wire and verified that the resistance was either low or infinite depending on key position as it should be.

It was just dead. After giving up, I came back to it a few hours later and touched the key and it started instantly. I turned it off and prepared to take it for a test spin. It started instantly, ran for perhaps 20-25 seconds, and died as if I had turned off the switch. No sputtering and coughing, etc.

I again pulled a plug and verified that there is NO SPARK.

Looked over wire connections/ground. Looked good ??

On my old tractor, the key switch is notirious for going bad and cutting off after a few seconds of running. Anything like this know for Yamahas?

I would appreciate any suggestions or hints for troubleshooting. I have a manual and they say essentially, got gas, starter turns, shut off (white wire)ok, change ignition parts.........

Thanks for any suggestions. I will have to tow boat to get it out of water and my crab pots need tending.
 

Popster

Seaman Apprentice
Joined
Jul 18, 2007
Messages
44
Re: Yamaha C115TXRS No start, no spark- intermittant

here's the update.

I know why the neutral safety switch seemed faulty- my rig doesn't have one.

The kill switch is good. Checked with meter and then check with power to motor.

The motor is getting 12v from the key switch.

The pulsar coil (whatever that does) resistance check was good.

Does anyone know how to do the CDI test from the Yammi manual. Do the wires stay connected to the terminal block (except for the overrev wire)?

Will check out the charge coil and the lighting coil tomorrow.

Need to know more about the CDI test. What does CDI stand for?

Checked connections and fuse.

Any help??? Anyone???
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,125
Re: Yamaha C115TXRS No start, no spark- intermittant

CDI = Capacitor Discharge Ignition
Do a on line search for marine CDI troubleshooting.
You will need DVA to read peak voltage.
 

Popster

Seaman Apprentice
Joined
Jul 18, 2007
Messages
44
Re: Yamaha C115TXRS No start, no spark- intermittant

Thanks,

Will do the research.
 

Popster

Seaman Apprentice
Joined
Jul 18, 2007
Messages
44
Re: Yamaha C115TXRS No start, no spark- intermittant

Update:

pulsar, lighting, and charging coils all test good via resistance test.
 

Popster

Seaman Apprentice
Joined
Jul 18, 2007
Messages
44
Re: Yamaha C115TXRS No start, no spark- intermittant

Thought I might help others who are searching.

Summary- tested pulsar, lighting, and charging coils per manual resistant test, all good.

Tested control box for stop switch, switch tested good

Had 12 volts switched on CDI terminals

Had friend who is Yammy mech put test harness on motor, same results, no spark.

He said the CDI (he called it the powerpack) was probably bad.

I took one of my spare parts motor, installed it, touched with key, and motor roared to life.

All is good.
 
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