Where should I start?

[Guest]

Hello,
I have an 84 interstate with 24,000 original miles. It sat for a long time so when I bought it I had to have the fork seals replaced and the forks too for that matter, as they were pitted from sitting in the same position for so long. I've put a few thousand miles on it since I bought it and have had no real problems, until now. I was riding this week and on the highway it runs great as usual. The weather is getting warm and so was the motor. When I stop at a stoplight and the engine goes to idle, sometimes it idles real rough, like its missing and the lights all flicker and tach bounces around. Much like a two stroke at idle, the power system seems to be pulsing with the engine. When I rev it up its fine and all the lights get brighter. Back on the highway it runs great as usual. The idle thing does not happen every time but is getting more frequent. I replaced the battery last year and its still holding a charge fine. Where should I start looking for trouble? Thanks in advance for any help. 8)

[Guest]

I would start with the charging system. When the motorcycle is turning higher rpms, the charging system is probably charging some, but when you drop down to idle, it stops charging and the battery is near the minimum voltage required to keep the bike running.

Check the battery voltage with the engine off, the engine idling, and the engine revving. Check the output of the stator. Check the voltage regulator.

[wpgfire]

May we assume that you changed out all the fluids? I would also guess those are 25 year old timing belts, though that wouldn't necessarily be causing your current problems. If it were a car and was acting that way I'd be looking at the alternator first. You may soon be having to make the BIG decision - new stator or poorboy conversion. The charging system is the best place to begin. There are lots of threads describing the process if you're one of the uninitiated.

[Guest]

Thanks for the starting points. Yep I changed all the fluids and replaced the tires (dry rot) I have been wondering if I should check the belts, sounds like a good time to check everything out while I'm down. I have read about the conversion and was hoping it was not that but seems like it might be. :| Thanks again for the input, I'll repost after I check things out.

[Ed Z]

I would be looking at the spark plugs and carbs for rough running of the engine... The charging system is really only around to keep the battery charged up... You don't even need a charging system if you have a constant 12 volt source... I have run my bike with a near dead battery with no real change in it's running... Had a friend that had and alternator fail on his 1500... Just swapped out batterys every so often till we got him home...

If you already haven't done so, a fuel filter and air cleaner would be in order as well... The timing belts should be looked at (and changed), but are not likely the issue you are having right now as they (if out of timing) would run poorly all the time not intermitantly...

[Guest]

All the other things mentioned are just collateral items. To address your specific problem, definitely start with the charging system first.

[Guest]

Thanks for all the ideas.
I finally got a chance to get out in the garage and break out the multi meter. I measured the voltage at the battery post. Cold with the engine off the battery is 12.7v
cold engine at smooth idle 12.2 v but it was not doing the flickering thing
cold engine at 2000 rpm 12.3 and at 3000 rpm 13 v.
I will have to check the manual to see what the output should be, but it does sound low.

[wpgfire]

That does sound low. At 3000 rpm it should be 14.5-14.9 range.

[Guest]

update number two.
I checked the manual and you are right on with the voltage that it should be. I did find something strange though. The electrical coupling (three prong) that goes from the alternator to the wiring harness was melted, looked very corroded. I have switched to a gel battery so it must have been leaking on it from the last battery. Some of the melt looks like battery leakage but the whole side of the connector was melted and two of the connections were touching and very chard looking. I cut the whole thing out and replaced it with individual connectors. Voltage went up a little but no more than 13 v anywhere in the rpm range listed in the manual. Looks like it is the alternator going out. But figured the bad plug might be something others might want to check for. Thanks again for leading me in the right direction.

[wpgfire]

You betcha, Reno. That looks like the 3-wire connector that tells the story of a fired stator. Goldwing 101 says, "When obtaining a GL1200 be sure to check the condition of the 3-wire stator harness. Options are to splice it out of there or clean and pack with dielectric grease." Though your battery may carry some responsibility for the condition of that harness it was probably primarily the excessive heat from the stator that caused the problem. Be sure you're sitting down when you get an estimate for replacement. I've heard as much as $1200 and up. You may want to search 'poorboy conversion' on this site and consider mounting an external alternator. Sounds like a bit of work to set it up but peace of mind in the long run. Also save yourself at least 50% over the cost of replacing a stator. I know I'm sure going to go that way if I still have the Aspy when the stator starts showing signs of wear. Still a good bike. Just needs some TLC and you'll be more attached to it than ever.

[roscoepc]

I have to differ with the 3-wire connector that tells the story of a fried stator. That just tells the story of a connector that went bad and burnt, not the stator! At 24,000 miles I'd bet a dollar that stator's good.

If it were me, I'd test the stator for AC voltage output. Should be between 50-70vac @ 3000rpm. If that's good, I'd suspect a bad regulator plus maybe a burnt regulator connector. If you need to know how to test the stator do a search. If you can't find it, let me know and I'll post the proceedure.

There's an old saying: You can't see the forest for the tree's..... So back to your other problem!!

The rough idle.

If you've got a fully charged battery, the charging system is not the cause of the rough idle. I'd start by changing the plug's, balancing the carb's,,, Basicly giving her a good tune-up and going from there.

Good luck with her!!

[Guest]

If it were me, I'd test the stator for AC voltage output. Should be between 50-70vac @ 3000rpm. If that's good, I'd suspect a bad regulator plus maybe a burnt regulator connector.

I second the motion. By the way, the generally accepted fix for that connector is to eliminate it - cut it out and straight solder the wires.

If you've got a fully charged battery, the charging system is not the cause of the rough idle.

I agree with this statement also. Put a good charge on the battery and see if the problem recurs. If it recurs while the battery is still strong, look somewhere other than the charging system. If it recurs after a few days of riding, check the battery. If the battery voltage is low, suspect the charging system.

[Guest]

Thanks again to everyone for the direction. Today I went out and took every electrical connection that I could get to, apart, cleaned dilectric greased and re-assembled. I don't know which one was bad, but now at 1100 rpm. the battery is charging at 14.25v and at 3000 rpm its around 14.75. I will have to road test it to see if the problem comes back or is still around. While I had some of the connectors apart I checked the resistance and/or continuity as per the manual and everything seems to be within specs. If everything continues to work I'll call it a day. If not I'll keep looking and testing. Thanks for the suggestions, I can't believe how helpful everyone is here. 8) :!:

[Guest]

Took the bike on a ride around town to see if the bugs were gone. Seemed to be, until I pulled up to a stop sign and everything just quit. I pushed to the side and started checking things out. The main fuse (dogbone) was in tact but sparking on one side. I disconned the neg. battery cable, removed, gently cleaned the fuse and replaced it securely. Everything fired right up and I went straight to an auto parts store, purchased an inline blade fuse holder and a couple of 30 A fuses. Went home and replaced the dogbone with the inline (just added a closed end adapter to each end and attached where the old dogbone went) I took it to work this morning and so far have not experienced any more problems. I am suspecting this was the problem all along as the old fuse just about crumbled when I took it out the second time. I have now read that this is pretty common on this bike. The alternator is back down to 13V so I'm sure its going but maybe I have a few more rides before it goes. Then I will be looking at the poor boy kit. Thanks again for all the help. I feel my bike is in better shape now than it was before.

[Ed Z]

I don;t think your stator is going, but rather you have a poor connector issue still at hand,,, Did you solder the three yellow wires at the connector area near the battery,???? Are you sure the wire was oxide free prior to soldering them??? If not to either the above, then you will need to correct that issue... Also, check the battery ground wire where it connects to the bikes frame... As stated earlier, I'll bet your stator is fine, but rather you have wiring issues that need attention...