93 2 stroke C115 Yamaha with no spark

[Capt_Tom]

Judging from some of the posts I have read, there appears to be some very knowledgeable people here. Great site!



I have a 93 C115 that started having troubles a year or so after I bought it. I would put the boat in the water and it cranked and cranked and never fired. I thought it was a fuel problem, as I had problems with a tank. After about 20 min or so cranking, waiting and cranking, it would finally start. It would then start every time all weekend. Then after a period of time it got worse,,,, It went to dealer after dealer, tech after tech... never found anything. THe last time I went to use it, I hooked it up in the yard, cranked it waited, cranked it, waited, and after 20 min, it fired as I released the key. After a little playing, it started. I ran it about 5 minutes on the hose. Drove 5 miles, attempted to launch it and it would not start. There is absolutely NO SPARK. This engine doesn't have the Yamaha computer, just the CDI box. I have a Seloc Yamaha manual that only covers through '88, but appears the same basic engine, and electronics as the book. Can anyone verify that for me? I have a digital VOM and a 12 volt test light. I ran the voltage and resistance tests called for in the manual, and couldn't get a determination. But definitely no spark from any coil. It calls for using a Yamaha test box, and I have none.

Quote JUSTINTIME in archived posting:

"u need to start to test components
check the coils first
then stator and pulser
i can get u the specs if u want"

Excuse the reply to such an old post JUSTINTIME, but could I trouble you for those specs?

Also, anyone with knowledge is welcome to chime in!

Thanks,
Tom Beckham
Pawleys Island, SC

 

[99yam40]

Re: 93 2 stroke C115 Yamaha with no spark

You need to get a Yamaha service manual for that motor and the proper test equipment.
hear is something to read up on as far as testing goes to give you an idea.

http://www.outboardparts.com/troubleshooting/printguide.htm

 

[rodbolt]

Re: 93 2 stroke C115 Yamaha with no spark

dissconect the white wire from the CDI box and retry.
be aware with the white wire dissconected and it starts you cannot stop it.
thats why we use spark testers.

 

[Capt_Tom]

Re: 93 2 stroke C115 Yamaha with no spark

Thanks for the replies. I will be home this coming weekend, and hope to get it going then.

By the way, if it starts with the white wire removed, what is the culprit?

 

[Capt_Tom]

Re: 93 2 stroke C115 Yamaha with no spark

You need to get a Yamaha service manual for that motor and the proper test equipment.
hear is something to read up on as far as testing goes to give you an idea.

http://www.outboardparts.com/troubleshooting/printguide.htm

I checked out the site. While it list universal test equipment, there is no testing listed for Yamaha engines.

 

[99yam40]

Re: 93 2 stroke C115 Yamaha with no spark

That was to give you an idea about how things are tested and they said that Yamaha is similar to Mercury.
As I said you need to get a Yamaha service manual for your motor so you will know the steps in testing and the specs.

 

[rodbolt]

Re: 93 2 stroke C115 Yamaha with no spark

its a dead simple ADI type ign system.
the charge coils,high and low speed,charge capacitors in the CDI unit,the two pulser coils are simply SCR triggers that allow the capacitor to discharge into the ign coil primarys.
the only real common spots that would affect all 4 cylinders is charge coil,CDI unit or the stop wire is grounded and your alarm doesnt work.

 

[Capt_Tom]

Re: 93 2 stroke C115 Yamaha with no spark

Thanks guys. looking forward to doing some testing this weekend, barring heavy rains

Rodbolt....

It is pre-mixed, and there was never an alarm on it... even if the kill switch was pulled.... Why? I have no idea.....go figure! But, this is a factory modified engine on the C115 commercial block. (heads worked, exhaust tube modified, timing bumped, & bois. reeds) Dealer ordered it prepared for "performance"..... I bought it like that new, and have always babied it. Hardly ever ran it at more than 3/4 throttle (except to blow some carbon at the end of the day.... no more than 3 to 5 minutes)

 

[rodbolt]

Re: 93 2 stroke C115 Yamaha with no spark

dealer is blowing smoke,or was.
Yamaha never offered that motor customized from the factory.
someone may have done it but not yamaha.
the alarm horn is in the control box on a 703 side mount or on the keyswitch assy on a 704 binnicale.
with the stop lanyard pulled and the engine cranking it should sound the alarm.
if you dont have an alarm you really need one.