Help me find spark on my SR500
- Thread starter scott s
- Start date
To add even more mystery and intrigue, I spoke briefly with Rick's, explained the situation and sent them some pics.
They said their technicians notes showed that my original unit WAS GOOD. My shop told them to rewind it anyway. Now it's definitely wrong and that throws suspicions back to the CDI.
So now do I have TWO new/rebuilt parts that are no good!?
The only way to make sure is to send both to Rex's. They have the jigs, parts and test equipment to test and repair properly.
I'm awaiting word back from Rick's.
They said their technicians notes showed that my original unit WAS GOOD. My shop told them to rewind it anyway. Now it's definitely wrong and that throws suspicions back to the CDI.
So now do I have TWO new/rebuilt parts that are no good!?
The only way to make sure is to send both to Rex's. They have the jigs, parts and test equipment to test and repair properly.
I'm awaiting word back from Rick's.
Even if Rick's tested it OK before, they have now rewound it and that pole is bent. My money is still on the weak pulse generated from that trigger and/or the ignition coil on the stator. But Rex's can test the whole system and advise what's wrong.
They should be able to determine if the pulse coil generates sufficient voltage and should also be able to put the output on a scope to see if it looks right. If it cannot generate a clean start end end to the pulse, so to speak, it cannot trigger the CDI or calculate timing advance. It probably generates a positive and negative pulse that the CDI uses to time the spark and even if the resistance is in spec it may not be able to create a spark.
REx's people should know what it needs.
They should be able to determine if the pulse coil generates sufficient voltage and should also be able to put the output on a scope to see if it looks right. If it cannot generate a clean start end end to the pulse, so to speak, it cannot trigger the CDI or calculate timing advance. It probably generates a positive and negative pulse that the CDI uses to time the spark and even if the resistance is in spec it may not be able to create a spark.
REx's people should know what it needs.
Got the stator and flywheel back on today. Pulse coil looks "normal" now, gap is good, etc. Still no spark.
I removed the (new) CDI unit and will be sending it to Rex's for testing. Do you see anything in these pics that would cause you to send the stator as well?
I removed the (new) CDI unit and will be sending it to Rex's for testing. Do you see anything in these pics that would cause you to send the stator as well?
Stator passes with flying colors.
I took out the screw on the pulse coil and made sure there was no epoxy on the rear where it touches the backing plate.
Tested the coil again: good.
Here's where things get funky.
While I had the test sheet out, I did ALL of the tests again and now I'm getting some funky readings on the key switch/kill switch tests. I have the results written down from before and now my numbers are different.
Especially the "KILL SWITCH OFF, IGNITION SWITCH ON" test. And that one gave me a high reading once before.
EDIT: set up some leads so I could test it by myself.
OK, definitely getting something odd on the ignition/kill switch circuit now.
I set up some leads so I could test it myself and then subtracted the resistance of the leads.
From Rex's test procedures, I get:
1A 0.6-0.7 ohms
2A 0.6-0.7 ohms
3A 260*
4A infinite
Test 3A, in my notes, had a star beside it and I got slightly high on a previous test, but nothing like this.
Maybe something has been iffy and failing up there all along?
If 3A is bad, which switch is it? The ignition switch or the kill switch? Is the only repair to replace it?
This was starred before, for reasons I can't remember now.
In the previous tests, even if I zero out for the leads I used, 3A still showed high.
But now it's insanely high. What does that tell me?
I took out the screw on the pulse coil and made sure there was no epoxy on the rear where it touches the backing plate.
Tested the coil again: good.
Here's where things get funky.
While I had the test sheet out, I did ALL of the tests again and now I'm getting some funky readings on the key switch/kill switch tests. I have the results written down from before and now my numbers are different.
Especially the "KILL SWITCH OFF, IGNITION SWITCH ON" test. And that one gave me a high reading once before.
EDIT: set up some leads so I could test it by myself.
OK, definitely getting something odd on the ignition/kill switch circuit now.
I set up some leads so I could test it myself and then subtracted the resistance of the leads.
From Rex's test procedures, I get:
1A 0.6-0.7 ohms
2A 0.6-0.7 ohms
3A 260*
4A infinite
Test 3A, in my notes, had a star beside it and I got slightly high on a previous test, but nothing like this.
Maybe something has been iffy and failing up there all along?
If 3A is bad, which switch is it? The ignition switch or the kill switch? Is the only repair to replace it?
This was starred before, for reasons I can't remember now.
In the previous tests, even if I zero out for the leads I used, 3A still showed high.
But now it's insanely high. What does that tell me?
And now I can't duplicate that odd reading. FML! 
I'm getting the exact same reading across tests 1, 2 and 3 and infinite on 4. But no spark.
I'm willing to pay someone to fix the damn thing at this point but I don't know of anyone in the area who would work on it.
I'm getting the exact same reading across tests 1, 2 and 3 and infinite on 4. But no spark.
I'm willing to pay someone to fix the damn thing at this point but I don't know of anyone in the area who would work on it.
Sonreir said:
Well, the stator was rewound by Rick's but they used the wrong size wire and they wound the low speed pickup incorrectly. Twice.
They had 3 shots at it. To their credit, they gave me a full refund.
I sent the stator to Rex's and got spark on the first kick. Fiddled with the carb settings and got it to run today. I need some fuel line so I can hook up the tank.
And I'm still having some issues with the LH control. I think the contacts are bad. Sort of a known issue on these bikes.
I saw a thread on the SR500 forum and he had the same issue I had; everything tested good but no spark. He had his "good" stator rewound and got spark. Same thing here. The stator tested good but it wasn't.
Well, I've put about 5 miles on her riding around the neighborhood. When she runs, she runs great. Falls into a nice idle (~1100 RPM), pulls pretty clean. Seems to really kick in over 3K RPM, probably when the pumper carb gives it a little extra juice. No real popping or backfiring anywhere; just a minor "chuff, chuff" on decel. Might just be the nature of the exhaust. The plug looks darn near perfect.
But HOLY HELL can she be a bitch to get started!! I kicked until I thought I was gonna pass out this afternoon.
I have the mixture screw set between 1.5 and 1.75 turns out (TM36-68 pumper carb). I started at 1.75 turns and went out, but that made the idle sluggish. Going in towards 1.5 turns cleaned up the idle and maybe helped with the "chuff, chuff" on decel.
When I installed the stator, I just set it in the center of the slots on the backing plate. Is there such a thing as "setting timing" on the CDI model? Maybe adjusting the stator position would help starting?
I've read where people with new coil, CDI and stator experience 1-2 kick starting. Something is obviously not quite dialed in on mine just yet. What would you check next?
I base lined the carb slide per some instructions member ASE-79 gave me. I did experiment with the idle screw (slide position) and, to be honest, I'm not sure where it is at now. You can't really bottom it out and start over without seeing the slide. But the fact that it idles darn near perfect when running makes me think it's OK.
But HOLY HELL can she be a bitch to get started!! I kicked until I thought I was gonna pass out this afternoon.
I have the mixture screw set between 1.5 and 1.75 turns out (TM36-68 pumper carb). I started at 1.75 turns and went out, but that made the idle sluggish. Going in towards 1.5 turns cleaned up the idle and maybe helped with the "chuff, chuff" on decel.
When I installed the stator, I just set it in the center of the slots on the backing plate. Is there such a thing as "setting timing" on the CDI model? Maybe adjusting the stator position would help starting?
I've read where people with new coil, CDI and stator experience 1-2 kick starting. Something is obviously not quite dialed in on mine just yet. What would you check next?
I base lined the carb slide per some instructions member ASE-79 gave me. I did experiment with the idle screw (slide position) and, to be honest, I'm not sure where it is at now. You can't really bottom it out and start over without seeing the slide. But the fact that it idles darn near perfect when running makes me think it's OK.
CarbsAndCylinders
Careful With That Axe Eugene
My SR500 has a big bore kit (540 cc), bigger carb and the battery has been eliminated. It is the most difficult bike to start that I have ever experienced, worse than a 1969 kickstart Sportster that had a big bore kit and cam. I have found that if it doesn't start after a few kicks then it's best to wait 5 minutes and then start over. Once started though, all is forgotten, a big single is sweet to ride.
