1996 C115 Yamaha dies suddenly

[hawilson2]

Cruising along and the engine dies. Does not seem to be a fuel problem because the fuel ball is firm and the internal fuel bowl with filter has fuel in it. Sometimes engine will restart right up other times it will not. Eventually it will start up and I am on my way. I suspect some sort of electrical problem. Maybe a ground issue? Maybe a problem with ignition switch? Thanks in advance for any help.

 

[jerkin]

Re: 1996 C115 Yamaha dies suddenly

I'm far from an expert, but my f115 had a problem like that. I did some searching here and found a post about a bad ground at the battery. I cleaned my terminals and tightened everything up and it hasn't happened since.

 

[Ray Neudecker]

Re: 1996 C115 Yamaha dies suddenly

The likely cause is a connection problem. Battery connections are the most likely place to start at both ends. I normally replace the thumb nuts with ones you can tighten down with a wrench.

 

[hawilson2]

Re: 1996 C115 Yamaha dies suddenly

I'm far from an expert, but my f115 had a problem like that. I did some searching here and found a post about a bad ground at the battery. I cleaned my terminals and tightened everything up and it hasn't happened since.

I lossened all gounds in the motor and retightened. I also cleaned all connects to the batteries, battery switch, and engine and retightened. I will see if that was the problem.

 

[hawilson2]

Re: 1996 C115 Yamaha dies suddenly

The likely cause is a connection problem. Battery connections are the most likely place to start at both ends. I normally replace the thumb nuts with ones you can tighten down with a wrench.

As mentioned above, I've cleaned and retightened all battery connections. I already am using SS nylon nuts instead of wing nuts. Thanks for the reply.

 

[Capt Ken]

Re: 1996 C115 Yamaha dies suddenly

If the engine dies like the switch has been turned off, then don't discount the ignition switch grounding out internally. Common problem since we all are free with the water when it comes to washing the boat. Doesn't take much corrosion in the switch to ground one out and kill the engine. Also the kill lanyard switch can cause the same problem.

 

[bernieb]

Re: 1996 C115 Yamaha dies suddenly

If your engine has a "system relay" it could be the problem. It should be in the early stages of + voltage coming from your battery. If it's not the ignition swich you may take a look ....expensive . When the engine dies does all your gauges die?

 

[hawilson2]

Re: 1996 C115 Yamaha dies suddenly

If the engine dies like the switch has been turned off, then don't discount the ignition switch grounding out internally. Common problem since we all are free with the water when it comes to washing the boat. Doesn't take much corrosion in the switch to ground one out and kill the engine. Also the kill lanyard switch can cause the same problem.

I changed out the entire switch/lanyard mechanism with a known working one from a friend and still the same results. It is now however not starting pretty regularily. I checked and I am getting no spark on all plugs. I need to test the ignition charge coil, pulser coils, and CDI unit. I have a clymer manual but the tests seem a little vague to me. Any info on testing any of those components would be appreciated.

 

[hawilson2]

Re: 1996 C115 Yamaha dies suddenly

If your engine has a "system relay" it could be the problem. It should be in the early stages of + voltage coming from your battery. If it's not the ignition swich you may take a look ....expensive . When the engine dies does all your gauges die?

The starter works so the system relay (I assume you mean main fuse) is fine. No, all the guages remain light and functioning. I am not getting speark as I mentioned above.

 

[hawilson2]

Re: 1996 C115 Yamaha dies suddenly

Well, replaced the CDI unit as a measure of desperation (in the middle of duck season and a long downtime was not a option). The new CDI unit seems to have done the trick. Runs like a charm . A little hard to start. I imagine I need to adjust the timing for the new CDI. Thanks to all that that replied.