Where's the coil/sender test info?

[endlessGSgeek]

I am having low rpm issues. Carbs seem good and jet properly. I thought it was bogging (too rich), but needs enrichment to start and plugs are not showing rich mixture.

I am pretty sure I saw something in the stator papers or elsewhere on sender coil testing, and coil testing. I'd like to see if either of those are obviously blown before checking stator output (charges OK). I've just put a new reg/rec in and have a couple of spare coils if a coil is the culprit. If it is the ignitor, oh cr@p!

Can anyone direct me to the sender coil testing procedure (and coils) ??

I am so upside down on this project, it is silly. Why do I do this (rhetorically speaking)...

[Billy Ricks]

This is for an '85 700 but you can probably use the same tests for your bike.

Here's how to check the ignitor. Remove spark plugs 1 & 2 and ground them to the motor so they will fire when they get power. With the ignitor facing you, the plug on the right side of the ignitor is where the signal generator plug fits. The two terminals on the right side of that portion of the ignitor will be pin 1 at the front and pin 2 at the back. The two left pins will be pin 3 in front and pin 4 at the back. Turn the ignition switch on. With a multitester set a the X1 ohm range put the + probe on pin 2 and the - probe on pin 1. Plug number 1 should fire. Next put the + probe on pin 4 and the - probe on pin 3. Plug number 2 should fire. If this happens the ignitor is good and the signal generators are suspect.

As for testing the pickups, signal generators, measure the resistance between the two wires on each pickup. You should get somewhere around 130-200 ohms. If the resistance is infinity or less than spec they are shot.

To test the coils put one probe of the multitester on each of the terminals on the primary side of the coil. You should get 3-5 ohms. Check the secondary windings by placing one probe into each of the plug wires coming from one coil. Those would be 2 & 3 from one coil and 1 & 4 for the other. You should get 30-50,000 ohms for stock coils and 15-20,000 for aftermarket.

[endlessGSgeek]

This is for an '85 700 but you can probably use the same tests for your bike...

Thanks. I'm heading for the garage.

[Zook]

Remember the generators may be having issues when they get warm. Test them with a hair dryer.

[endlessGSgeek]

fix made NEW problem

1-4 coil was over 100k. I installed the used coil from a 750 that tested high (near 50k) but within range. Of course it started, but wires from stator get HOT fast. Fortunately, my right wrist felt the heat while replacing pods. They really heat up right away, and will obviously melt If connected (current flowing).

CAN I disconnect the stator for a short test ride? Will it burn the Reg/Rec or something else ? I can resist the temptation, but curious if the used coil restores low end power.

Next issue is testing stator. I'm skeptical. Why the extreme heat in the wires??

[endlessGSgeek]

This is for an '85 700 but you can probably use the same tests for your bike.

the new aftermarket reg/rec has nothing to do with it. I replaced the old one, and same thing. HOT stator wires quickly after startup. Seems to run strong. I'd like to disconnect the stator at test the coil fix (low end power) Will this damage anything electrical?

Do you disconnect the stator for stator voltage output testing?

[Billy Ricks]

You do disconnect it for voltage testing. It won't hurt the r/r, diodes only flow in one direction. Assuming the battery is fully charged it will run off the battery. If wires are heating up you have too much resistance somewhere. Go through all the wiring and clean up connections and make sure they are tight. Check the fuse block. Open it up and clean those connections and recrimp the female terminals. They get loose over time and cause too much resistance. The r/r could also be too hot and putting out too much voltage.

[endlessGSgeek]

Thanks. I'm heading for the garage.

I'm quoting myself because I DID head for the garage and make the coil resistance measurements (primary resistance is 1.5 for point systems or 2.2 ohms for coiled pickups? but seem NOT to be the problem), but now finally (seems like months later?) managed to test stator output.

Stator output test on 1982 GS1100G.

Three wires:
Green with white stripe (Gw)
White with blue stripe (Wb)
Yellow (Y)

I tested AC voltage wire to wire:

Wb to Y makes 70V at 4000 rpm, 85V at 5000rpm, over 100 at high rpms

Gw Y makes 70V at 4500rpm, near 90 at 5000 rpm, over 100 at high rpms

Gw to Wb makes only 55V at 5000rpm
makes 70V but only at 7000-7500rpm

The stator wires seem to get hotter than they should when running, even with a fully charged battery! Running disconnected (no heat, of course), or connected (hot to touch), doesn't change the low rpm stumbling, so I am tragically back to carbs (pilots or airjets). Someone reminded me that coil problems are worse at higher rpm, so I need to troubleshoot low end circuit carburation. I'll start with airjets using colortune.

[endlessGSgeek]

I failed to admit that the low end stumbling/missing is unrelated to the hot stator wires. Apparently stator wires get hot (some bikes, or most?). AND, coils fail worse at high rpm than at low rpm, so Anyway, the low rpm misfiring problem appears to be carbs. Oh gee. I have removed and cleaned, inspected them probably a half dozen times. Sigh. Float height, airjet port clear, all jets clean, etc. Only thing I havent done is those airscrews in front "one and three quarters open". Hard to adjust without remote tank setup. Damn (sorry).