1989 Yamaha 225 Excel - No Spark

[BigNiner19]

No spark to the motor. Cranks hard, wants to fire up, but checked for spark and only getting VERY WEAK spark to ONE cylinder.

Started checking the key switch up front, everything had continuity where it is supposed to EXCEPT the pink wire coming off the switch/harness. I do not know what the pink wire on this particular harness is for, but everything else checked out okay.

What else can I do? Pulsor coil? Stator? How do you know if the computer itself is bad? I hate ignition trouble shooting.

What does the pink wire do?

Cory

 

[jeffersondodson561]

Re: 1989 Yamaha 225 Excel - No Spark

On the back of the micro-computer is a yellow bullet connector, I think you connect it or disconnect it, to bypass the computer. This will make it operate just on the CDI principle. Yamaha ignition is really hard to see period. The pink wire is the warning horn sending wire. This is basically a CDI motor above 4500 rpms. You need a DVA and multimeter to determine what is bad. Yamaha Microcomputers are very good, I have never seen a bad one. I would check spark by doing spark check with a timing light. Also do a ohm test on the crankshaft postion sensor. Blue to Blue 740ohms +/-10%

 

[BigNiner19]

Re: 1989 Yamaha 225 Excel - No Spark

Forgot to do the crankshaft position sensor before it got dark. But I checked everything else over. I did not get any continuity from the stator or rectifier. The Pulsor coils and harness all checked out fine on the multimeter. The stator does not appear to be damaged. I'm having a tech out at Pratt and Whitney check it over and see if thats the true culprit or not.

I find it hard to believe a stator could go bad. But everything else is checking out just fine. I pulled the white/black wires for the kill switch, still no spark. So as it stands...

Key Switch - Check
Kill Switch - Check
Pulsor Coils - Check
Harness - Check
All other harnesses/grounds looks good.

Cory

 

[blindmullet]

Re: 1989 Yamaha 225 Excel - No Spark

Neutral safety switch on the throttle? Disconnect them and try to start it-- 2 brown wires coming out of the 704 box or complete the circuit by putting them together.

 

[jeffersondodson561]

Re: 1989 Yamaha 225 Excel - No Spark

It's not uncommon for a stator to fail, if your going to use resistance test use these specs. I would feel more comfortable getting the voltage output rather than resistance, I usually use them as a back up conformation after voltage is read. The manual does not give voltage spec but it has high/low speed windings and you can pretty much tell when it is not functioning properly. Just remember that before you test for resistance, touch your meter leads together and make sure no unwanted resistance is in the meter.

 

[BigNiner19]

Re: 1989 Yamaha 225 Excel - No Spark

It's not uncommon for a stator to fail, if your going to use resistance test use these specs. I would feel more comfortable getting the voltage output rather than resistance, I usually use them as a back up conformation after voltage is read. The manual does not give voltage spec but it has high/low speed windings and you can pretty much tell when it is not functioning properly. Just remember that before you test for resistance, touch your meter leads together and make sure no unwanted resistance is in the meter.

I'm having a difficult time trouble shooting this. Jeffersondodson, you are in west palm. Do you think I can bring my stator to you and get a hand at trouble shooting it to decide if its bad or not? Dont want to make a $350 mistake.

Cory

 

[jeffersondodson561]

Re: 1989 Yamaha 225 Excel - No Spark

No I need it on the engine with a fully charged battery. I would have to come to you. I would not charge you, if I fix it however I would not refuse a gratuity. I live downtown what part of the County do you live in? What is your schedule? I am available Friday or Saturday. Would need access to an outlet/estension cord if you got it, fully charged battery and water/if we get if running.

 

[BigNiner19]

Re: 1989 Yamaha 225 Excel - No Spark

I would greatly appreciate some good knowledge and help.

Okay, right now I have the stator off as well as the fly wheel, but it can all be put back together. I thought the stator could be tested off the motor as I'm pretty sure thats the reason, but if we would have to put it all back together, its not to difficult to get it back out. I did however, break my puller for the flywheel.

Saturday morning would work the best for me. If its even easier, I can drag the boat down to you, so all your tools and everything would be there. I have a fresh battery. If not, I think I've got everything else we would need.

I live on the north end of the county in Jupiter near Donald Ross Rd

Cory

 

[jeffersondodson561]

Re: 1989 Yamaha 225 Excel - No Spark

I have a set of portable tools that will work however I do not have a torque wrench we will need on if you can get your hands on one, don't worry about the puller their are ways around that. I can be there as early as 10 am on Saturday. PM me your details and we will take it from there.

 

[BigNiner19]

Re: 1989 Yamaha 225 Excel - No Spark

Would like to thank Jeff for helping diagnose my electrical issues. It was nice to meet you and learn from your knowledge.

Guys, if you have an electrical problem, dont overlook some of the simple things. My motor had spark, but also had 3 bad resistor caps. That will keep a motor from ever firing up.

Thanks again Jeff

 

[chris0405]

Re: 1989 Yamaha 225 Excel - No Spark

Would like to thank Jeff for helping diagnose my electrical issues. It was nice to meet you and learn from your knowledge.

Guys, if you have an electrical problem, dont overlook some of the simple things. My motor had spark, but also had 3 bad resistor caps. That will keep a motor from ever firing up.

Thanks again Jeff[/QU



Sounds like a friends motor has the same problem. A mechanic told him it was the trigger. He wants to sell me this boat but the motor has no spark. Any quick checks to determine why no spark?

 

[BUBADOO]

Re: 1989 Yamaha 225 Excel - No Spark

hello guys i was reading your thread because Iam having the same problem with my engine
can you please yet me know how everything turned out
I have no CDI OUTPUT but inputs are good and kill wires are off.