2002 Yamaha Bear Tracker No spark

[pastorjeep]

Need some feedback here. I picked this machine up with PO saying no spark. I have tried new stator, CDI, and coil. The stator ohms 231 w/r to w/g and .1 red to blue. The coil is .8 primary and 2.53 secondary. I have 12 to the CDI with ign on and the wires from stator to CDI have good continuity. This model only has 12v on or off for ign/kill source. Still no spark? 

[Mech]

Have you checked the earths ? Especially the cdi and coil, but they have to be connected to the frame, battery and engine eventually, so you need to check all the earths everywhere..

Continuity from cdi to coil ?

[pastorjeep]

I began to wonder if it was a ground issue, so I ran another cable from the frame to the engine.

[pastorjeep]

What is the AC voltage that should be coming from the stator and trigger coil? 

[Mech]

Get a service manual and it will spell out the diagnosis process and most of the information you need.

A lot of manuals only tell you the resistance of the windings, but if the magnets or trigger plate have fallen off the flywheel then there isn't going to be any power or trigger induced. I always put a gauge on to check the flywheel is turning and the magnets etc are still there and inducing some current. Exactly how much current doesn't really matter as long as the resistance is correct on the coils. The trigger pulse is very short and some digital gauges don't detect it. It's better to use an analogue gauge because you will see the needle flicker strongly.

And.. did you check the cdi and coil both have an earth ?

Did you check for continuity from cdi to coil ?

[pastorjeep]

Thanks for the reply. These are the kind of thinking I need. I know that I have always done resistance test on stators on the past but it seems that voltage tests are the new thing. That would tell me if it is actually sending a signal and not juts passing the resistance test. I did check the orange wire from CDI to coil and the the common ground shared by the regulator and CDI as well as the coil ground. As stated earlier I added a ground wire to the engine because Yamaha doesn't use one. Right now getting a service manual is not an option. 

[Gwbarm]

There is a common ground on Yamahas, it appears to be a cooling fan ground that is mounted under one of the coil mounting bolts but it does more, you might check and see if that wire is intact or check for the fan ground. There are 2 coils involved in ignition and you can check to see if they are putting out voltage. The pickup coil and the antikckback coil, they put out very minimal voltage which cannot be read by a digital meter, you need an analogue meter with a needle and the needle will move if they are putting out voltage. I cant remember the exact numbers. You test these coils along with main coil 12 volts to the CDI along with a good ground and if all pass the test along with the start stop switch function test and still no spark, manual says replace CDI. There are 2 relays close to the battery you could also check.

[Mech]

Some models have a join in the earth wire hidden away inside the loom.. They can actually have several crimp earth connectors, and power connectors, hidden inside the loom.

Oh, and some makes and models they do suggest resistance test and an output test..  It's not new. I always do an output test whether I have a figure for it or not..