possible coil problems

[kirbstone]

Hi I'm hoping someone can give me some good suggestions or name a place that I can take my motorcycle to and get it fixed.
I own a 97 vmax that started acting like my plugs were fouled or the sparkplug wires were bad so I took it to one motorcycle shop and had them replace the plugs and wires along with a coil that controls the spark to #1 cylinder which they told me was bad. I than took it out on the highway and after a few miles it started acting like the plugs were fouled again. The shop people couldn't figure out what's causing the problem so I took my bike to a second shop and they told me that the cylinders were getting fuel and all four plugs were working but after about 10 minutes of riding 3 of the cylinders cut out and they can't figure out why. Does anyone know of a really good Yamaha shop in the New England area that could figure out what is going on with the electrical system. I'm located on the north shore area of Mass.

Thanks for any suggestion on how to fix this or a good shop to take this to.

 

[rhoke]

Well, it sounds like to me that when you warm it you are having problems? I have read before that if you pick-up (in the stator area) does react to heat if they are on the verge of malfunctioning. Sorry dont know of shop near your area. hope this helps Roy Good thing is there isnt much to your Starting and ignition systems.

 

[kirbstone]

Hi rhoke,

Thanks for tip I'll look into the stator and see if I can find out what that does as well as look into getting it tested and replaced if nessary.

thanks again.

 

[Akatora]

Hello,

There are orange and black wires coming from the stator. The connector joint should be under the saddle. You can verify / rule out this (pick-up coil) problem with following method:
- locate the connector joint so that you know where it is
- prepare ohm meter (multimeter)
- start the engine and let it run or ride it until the problem occurs
- turn off the engine, remove the saddle and open the connector joint
- measure the resistance between orange and black wires that are coming from the stator side of the joint, the specified value is 81 to 121 ohms at 20 degr. Celsius (practically this value can be somewhat outside these limits depending on the temperature)
- if the measurement shows no continuity (infinite resistance) or considerably high resistance value, it is likely that your pick-up coil is faulty

Note: It is important to carry out the measurement immediately when the problem occurs. If you switch the engine off and wait for a while, the coil cools down and the problem might not be found.

Good luck!

P.S. While you have the multimeter, it is also good idea to check the voltage between the battery poles with and without the engine running. With engine not running, the voltage should be near 13 volts. With engine running, something like 14...14,5 volts.

AT

 

[kirbstone]

Thanks Akatora,

I'll check that out this weekend. Would you know where the stator is located?

 

[Akatora]

Hello,

The coils are bolted inside the left side cover (flywheel generator cover).

To check the pick-up coil problem, you can follow the wire harness that is coming from there and going upwards near the left foot rest. The connector is under the saddle and that's all you need to find. No need to open the stator cover to conduct the coil inspection. Just locate the connector joint under the saddle and disconnect it to check. There are actually two harnesses coming from the stator cover, one containing the orange and black wires (pick-up coil), and the other containing three white wires (alternator). You are only interested about the resistance between the orange and black wires.

If the pick-up coil turns out to be bad and you have to change it, first you need to drain the oil, then remove the gear change lever. Then remove the small cover behind the gear change lever and after that the flywheel cover. Prepare new gaskets for both of the covers before reassembly.

The coil is bolted into the cover. Note that when removing the flywheel cover, the sprockets between the starter motor and starter clutch may drop out. They are easy to install back. There is no need to remove the flywheel (rotor).

If the measurement suggests problem with the pick-up coil, it is however first good idea to check the joint and then the condition of the wires between the joint and the coil.


Regards,

AT