Questions About Rectifier Testing

i feel your pain. Did you check the coil's resistances, both primary and secondary side? Chapter 16 of the FSM has the troubleshooting guide for the ignition system--other than that it would be a matter to trace and verify all the wires and components related to ignition.

Maybe there is something in there that a previous owner did that is not obvious--used bikes can have unbelievable mods and repair hacks, and you can't assume anything is good without verification.

 

The coils are all good. They all test fine resistance-wise. It's driving me nuts bc everything is checking out fine. Everything is grounded fine now (the PO did a hack job at cutting off "extra" bits). Everything I test tests fine... The R/R, the coils, the pulse generator, all the cut-out switches... They're all looking good. There's continuity when and where the should be, and there's none when there shouldn't be. There's a gremlin in there somewhere, but I just can't find it.

 

Start at the top of the troubleshooting chart on page 16-3 No spark at all plugs, and run thru it now that you have the new ICM and pulser, make sure to follow each step and the culprit will be outed.

Make sure all the wires and connections into the ICM are present and accounted for--just one cut or missing wire will cause chaos...

 

I followed each step and still don't see a spark. The only thing that doesn't check out 100% is the pulse generator test. That checklist says that it should test between 450 and 550 ohms. I'm getting 309 ohms on both. HOWEVER, a few pages down, page 16-7, it says that standard is 200 - 400 ohms at the 4-pin connector, which is the result I've gotten before when I tested that particular connector (the one by the pulse generator, not the ICM). Furthermore, both the "new" pulse generator and the one I took off the bike both gave the same reading: low 300s.

That being said, I sprayed a little starting fluid into one of the cylinders and a little bit into the airbox and cranked it. I heard a distinctive "catch" for a cycle or two and when I pulled the plug, it was brown. It looked to me like it fired. Now the question is did it fire bc there WAS a spark, or was it just the starting fluid detonating on its own, without the help of a spark, due to the compression in the cylinder?

I'm off to get a tank of gas and some hose. I put the battery back on the charger so I can start fresh.

 

Well I couldn't get anymore combustion with starter fluid alone. I'm also not getting any gasoline to the carbs... I discovered that my fuel pump isn't working. The pump itself runs just fine if I jump it, but it's not getting power when I hit the starter. That's how the pumps work on these bikes, right? Hit the starter and the pump goes on? I think I read that somewhere... On my Yamahas, the pump comes on when you first turn the key and have the kill switch on "run."

I guess I'll be looking into that tomorrow.

 

Ok, well it turns out that the fuel pump relay was bad. Replaced it with a new one, but it still won't run when I push the start button. Everything is testing out fine, though...

As far as the spark situation... Nothing new on that front either. I finally got my hands on an actual FSM, and followed the troubleshooting step-by-step. The only thing that concerns me is the pulse generator.

The FSM and the Haynes give different directions when testing the pulse generator. The FSM says to test resistance at the black connector, between the White/Yellow and Yellow terminals and the White/Blue and Yellow terminals. The W/Y-Y test gives me a good 300ohm reading. The W/B-Y test gives me 0. The FSM says it should be between 200 and 400

Now the Haynes says to test the same W/Y-Y terminals. However, the other terminals it says to test are the Blue/White and Blue. I do THAT test and I get a good 300 reading.

Thoughts?

 

Maybe a bad connector? The yellow is common to both coils in the harness from the ICM, so you should get a reading with yellow and white/yellow, and then the yellow and the white/blue. On the other side of the connector the blue wire mates to the yellow, so on the inside toward the pulse generator it is paired as yellow to white/yellow, and blue to white/blue. disconnect the 4pin connector (black) and make the measurement on the side toward the pulse generator, not toward the ICM.

 

Now, are you talking about the ICM side of the connector? I've only been testing the Pulse Generator side. I thought that's what the FSM specified, but I could have read it wrong. I dont have it in front of me, I'm in Vegas until Friday.

That's exactly what I've been doing, testing the PG side of the connector. The side with the Yellow, White/Yellow, Blue, and White/Blue wires. I'm not getting any reading between the Yellow and White/Blue wires on that side of the connector. The manual says I should, but if it's talking about measuring those wires on the ICM side... Well, that changes things a bit.

 

On the PG side you will get no reading between yellow and white/blue--it is a separate coil. Only when measuring on the ICM side with the connector mated will the yellow to white/blue read anything and then that is ONLY IF THE COIL IS GOOD. Best to check on the PG side with the connector open, repeating....
on the inside toward the pulse generator it is paired as yellow to white/yellow, and blue to white/blue. disconnect the 4pin connector (black) and make the measurement on the side toward the pulse generator, not toward the ICM.