Help me find spark on my SR500

[DaveO]

"I probably misstated earlier about power the coil. I believe what he did was bypass the harness and went straight to ground and coil. "

The spark happens only when the power is broken to the coil. If you supply power to the coil to continuously (with two wires) I think you run the risk of burning it out. (others with more experience may confirm). Depending on the sequence of events you may have ohmed out a good coil and then burned it out by running seperate wires.

 

[DaveO]

This is where the 12v comes in from the mysterious system "down below". If you are not getting a pulse of 12v from these two black and orange wires as you kick the bike over with the ignition on, then I would have thought this is where the fault lies.

Others with more experience may care to dive in here.

Dave

 

[DaveO]

Have you checked out the SR500\400 forum?

Nah, we got it.

 

[Brassneck]

Ya, doesn't look like there are any safety switches...wish it were that easy.

 

[scott s]

Nah, we got it.

Hehe.... yes, I am on the SR500 forum. And I'm asking a few other places, too. This is one of the strangest things I've run across working on old bikes.

 

[hogtyed]

You may have already read this. If not, it’s worthwhile.

https://yamahaclub.com/forums/topic/8213-78-sr500-no-spark/

 

[scott s]

Some random, thinking out loud questions, for when we do the next round of tests.

- If spark is killed by grounding the CDI (yes, we tried the trick of removing the ground wire), if the main harness has some unseen ground....say, along the frame or in the headlight bucket....would that kill the spark?

- If so, would the harness test good for continuity (it does)? Also, the tests that Rex's has for the ignition switch and RH control/kill switch are done at the rear of the bike, back where the stator and CDI plug in. That takes into account the wiring harness. But we've tested each component separately too. Would an unseen ground that kills the CDI have shown up during those tests?

 

[MalkyB]

Hi Scott - did you ever get a fix for the no spark. I'm going round & around trying to get a spark out of my Suzuki GT500 and it sounds like I'm having a similar issue. I've replaced almost everything other than the flywheel rotor.....correction I think I have replaced everything but the flywheel rotor!!!

 

[scott s]

The flywheel was rewound improperly by Rick's. Three times.

I got my money back and Rex's did it properly and I got spark right away.

I got it running but never got carb settings just right for easy starting. I just about ruined my ankle working on the thing (it's still messed up) so I sold the bike.

 

[Ostkuste]

The flywheel was rewound improperly by Rick's. Three times.

I got my money back and Rex's did it properly and I got spark right away.

I got it running but never got carb settings just right for easy starting. I just about ruined my ankle working on the thing (it's still messed up) so I sold the bike.

 

[Ostkuste]

I’m having same issue with my sr500, text me if you can Scott
980-521-8138 I’m north of Concord