Ignition breaks up after warm up R/R?

[hitman46mod]

Box fan in front of motor on high. Full choke, turn on the ignition hit the starter and she starts right up. After about 30sec I begin to turn off the choke 1min into start up the R/R is getting uncomfortable to keep a finger on after 2mins it is impossible to keep a finger on it for more than 2secs. Choke is now off. Bike idles fine. R/R is now scorching hot you cant even touch the wires coming off of it. At this point off idle to about 6k the RPMs wont stay steady and the motor hesitates while increasing the throttle. At the 5min mark she will not idle smooth. it drops and then smooths out over and over. She was running fine 2 days ago, then developed a small stumble at 3500. Then yesterday she began to break up at anything over 2k. I still have the stock R/R. Now you can't even ride it down the street with out it having a seizure, while giving it gas.

This of course could be damage from the ground issue I had in the headlight wiring. I fixed that and now I don't have an issue with the lights getting randomly brighter. But now this. So am I looking at a new R/R? Cause everything checks out in the charging circuit. Stator is in good shape as far as output tests. The Ignitor is cool to the touch the whole time. Or should I be looking at the coils? Any input would be awesome! Thanks for looking.

[bccap]

Have you tested the rr ? Battery with ignition on, at an idle, 5000 revs ?

[hitman46mod]

Yeah just came back in from doing some more testing. Ran a new ground from the R/R to the battery -neg. The R/R has consistent voltage. 13.7 to 14.2 the stator output is clean. However, I found something interesting. The coils are not getting 12v+ the right is between 4.3 to 9.6. the left is 3.6 to 6.4 and the readings are all over the place. When it starts stumbling, if I pull the right coil wire is stalls. If I pull the left it struggles real hard to stay running. I will have to run some more tests. But I'm thinking somewhere between the igniter and the coils I have a problem.

[tom203]

What is the voltage at coils with ignition on but bike not running? orange/white wire to good ground. When bike is running, ignitor is grounding out coils at right time- this would give a multimeter fits.

[hitman46mod]

That is a good guestion. I checked the voltage of the coil positive to battery ground with the key on motor not running. I got battery voltage. But I ran out of time and had to goto work. I need to read through the coil an ignitor test procedures. And do some more testing tonite.

[rapidray]

USUALLY, when a Suzuki starts to run rough after warming up, like you are describing, a coil is going. Ray.

[Nessism]

Sounds like your harness has a lot of resistance. Best thing is to clean all the connectors by removing the terminals and pinching the females closed. Failing that, you can perform the coil relay mod. Also, make sure to eliminate the out and back stator loop going to your LH hand control.

[hitman46mod]

Sounds like your harness has a lot of resistance. Best thing is to clean all the connectors by removing the terminals and pinching the females closed. Failing that, you can perform the coil relay mod. Also, make sure to eliminate the out and back stator loop going to your LH hand control.

How does the harness just develop a lot of resistance? I have put 2300 miles on this bike in the past 2.5 months, then this. I think it's Gremlins.

[rapidray]

How does the harness just develop a lot of resistance? I have put 2300 miles on this bike in the past 2.5 months, then this. I think it's Gremlins.

Did you read my post above? Ray.

[Nessism]

Ray is right that you most likely have a misfiring coil, but the reason is likely to be the low voltage.

Old harnesses often corrode down in the connector terminals. Best thing is to remove the little brass terminals from the plastic shells and clean them, and pinch down the female terminals before reinserting the terminals back into the shell. Again, failing doing this, do the coil relay mod and eliminate the stator wire loop. You can even reuse the harnessing wiring for the stator loop to feed the coils after you add the relay. Tons of threads in the archives on both these subjects, plus Basscliff has info on his site.

Good luck

[hitman46mod]

Ok, guys thanks for the info looks like I have a lot of wires to hack out today. I will give an update later.

[hitman46mod]

Ok, poured over the wiring diagram for my bike and visually looked myself. There is not a loop wire from the Stator on my 83' 450 to the right handle bar. So I don't need to remove that. I get .2 ohm resistance in the harness from the Ignitor to the Coils. The coils have 3.9 Left and 4.0 Right ohms across the terminals. I do believe I have a bad spark plug boot on the left side. When I unplug it and hold it away from the motor I feel a slight tingle in my fingers. I don't get that sensation on the right plug boot. And as i stated before if I pull the right plug wire the motor dies. So I started the bike and took it for a ride with the left plug wire pulled. Ride is smooth just not a lot of power. If I plug the left back in, runs mike crap! So I guess I will be looking for new coils or boots Seeing how my wires are permanately attached to the coils. I tried to take my boot off. No go, so I think I'm looking at coils. 83' GS 450 L Suggestions?

[hitman46mod]

Ok, poured over the wiring diagram for my bike and visually looked myself. There is not a loop wire from the Stator on my 83' 450 to the right handle bar. So I don't need to remove that. I get .2 ohm resistance in the harness from the Ignitor to the Coils. The coils have 3.9 Left and 4.0 Right ohms across the terminals. I do believe I have a bad spark plug boot on the left side. When I unplug it and hold it away from the motor I feel a slight tingle in my fingers. I don't get that sensation on the right plug boot. And as i stated before if I pull the right plug wire the motor dies. So I started the bike and took it for a ride with the left plug wire pulled. Ride is smooth just not a lot of power. If I plug the left back in, runs like crap! So I guess I will be looking for new coils or boots Seeing how my wires are permanately attached to the coils. I tried to take my boot off. No go, so I think I'm looking at coils. 83' GS 450 L Suggestions?

[Nessism]

Ok, poured over the wiring diagram for my bike and visually looked myself. There is not a loop wire from the Stator on my 83' 450 to the right handle bar. So I don't need to remove that. I get .2 ohm resistance in the harness from the Ignitor to the Coils. The coils have 3.9 Left and 4.0 Right ohms across the terminals. I do believe I have a bad spark plug boot on the left side. When I unplug it and hold it away from the motor I feel a slight tingle in my fingers. I don't get that sensation on the right plug boot. And as i stated before if I pull the right plug wire the motor dies. So I started the bike and took it for a ride with the left plug wire pulled. Ride is smooth just not a lot of power. If I plug the left back in, runs like crap! So I guess I will be looking for new coils or boots Seeing how my wires are permanately attached to the coils. I tried to take my boot off. No go, so I think I'm looking at coils. 83' GS 450 L Suggestions?

The spark plug caps unscrew from the wires, and the wires likewise attach to the coils over a spike in the coil (not threaded this time). Each plug cap should have 5k ohms resistance. NGK makes suitable replacements which are cheaper than stock if you need some. You can replace the wires by pulling them straight out of the coils (if you get lucky), but some times you have to dig out the remnants of the wire down into the recess area of the coil using a pick or similar.

It's common process here to remove the plug caps, check the resistance, and assuming they are okay, reinstalling them back onto the existing wires after snipping off a small section to freshen up the electrical contact.

You need to make sure the coils are getting good voltage. Your 450 DOES have that out and back stator wire loop so you better go back and check the wiring diagram again. You should bypass the factory wiring and hook up your stator directly into the R/R. Also make sure your R/R is properly grounded as Suzuki's R/R grounding scheme on many GS's was very poor.

[hitman46mod]

Ok, I only have 5 wires running to the right handle bar. Starter switch, cut off, and brake light. Here is the diagram. please show me where it connects.