Electrical problems on 1986 XLH.... PLEASE HELP

[adamz1le28]

I have had my 1986 XLH for about 3 years now. It was an 883, but I got it converted to a 1200, along with belt drive. Ever since I got the bike, when you start it, you cannot turn on the lights (it has the old ignition where you can have the headlight and running lights off until you turn the key to the third position) or it will "pop" and backfire. You have to start the bike with just the ignition on, ride around for a little bit to warm it up, and then you can turn on the headlights and running lights. Even if you hit the brake so the brake light comes on, or if you turn on the directionals, it will pop and backfire until it is all warmed up. Once the bike is warm though, these issues go away.

Another weird problem with the bike, I don't know if this is related to the same problem, is that it fouls spark plugs very easily. If you don't use the choke just right, it will foul the plugs and do the "popping" and backfiring. Please let me know what you guys think. Thanks.

[whiffy]

Sure is weird.
Is the battery well?

Whiffi

[thunderpaw]

If the battery and connections check out, you may want to test the voltage regulator and then the coils. Sounds like a weak spark to me.

Kim

[stevo]

once the engine is warm it takes less spark to ignite....

Also after start-up the alternator is tryin hard tp put the juice back into the battery...

It sounds like you have either/and a battery goin south, maybe loose magnets in your altenator, regulator problem.....

I'd go with the a new battery first and check the outputs of the others with a new battery on board

[adamz1le28]

Yes we recently put in a new battery and the problem persists. I was suspecting possibly a bad alternator. I'd sure like to get this fixed though. Maybe the regulator could be bad? Someone told me it could be the stator?? I don't even know what that is.

[dwardy]

Someone told me it could be the stator?? I don't even know what that is.

The stator is basically the "business" part of the alternator. It's stationary and the rotor, containing the magnets, rotates around it, generating voltage.

http://i12.ebayimg.com/02/i/02/a4/73/bf_1.JPG

[HrdlyDangrs]

This happened to me with several of my old motorcycles. There are several things you can check such as:

Battery & Connections...You said you already replaced & Checked

Timing........................Re-check timing and re-gap the points
Plugs & Wires...............When were they last changed?
Manifold Intake leak......Check for intake leaks at the manifold connections
Overly Rich Carb...........Adjust or re-jet


Since you stated that the problem has occurred since you purchased it, its possible that its the switch design itself......For instance..on both an Ironhead Sporty and B/T with Fatbobs with the dash mounted ignition switch ...I've had the same occurance.

I believe whats actually happening is that when you turn the switch from start/run to lights/accessories, you momentarily break the electrical connection from the battery to the coil, in effect turning off the bike for a split second, then as you turn the switch from 'On/Ign' to 'lights/access' it remakes contact, igniting all the fuel/air mixture in the cylinders from the revolutions of the engine that have taken place in between the time you 'shut down the circuit' until its turn back on. The only differance is that mine did not backfire when I stepped on the brake.

I never had the problem on my bikes with an ignition switch and separate light on/off switch.

[whiffy]

Yes we recently put in a new battery and the problem persists. I was suspecting possibly a bad alternator. I'd sure like to get this fixed though. Maybe the regulator could be bad? Someone told me it could be the stator?? I don't even know what that is.

From what you say, if you changed the battery, it is not likely to be the battery, it could be a number of things.

Check that the battery is being charged with a voltmeter. The positive lead should go to around 14V DC with the engine running. If the voltage is not close to 14V the battery will not charge.

If the voltage is incorrect it could be the regulator, check its output without the battery connected to the regulator. A dummy load is advised (another battery) to be connected to the reglator to put this under load. You will need to rev the engine a bit to get the alternator to produce a good output, 2-3000 rpm should be enough.

If the output is not high enough it could be the regulator itself, or the alternator, so check the alternator output, this should be way over 20V AC.
If you get the primary off and the alternator looks and smells 'cooked' get a new one!

Check all of the wiring and the connections for broken or damaged/bare wires.

It could be your ignition switch.

It could be ignition components.

If you do not know what you are doing take the bike to the dealer, or find a good local auto electrician to do the work for you.

Whiffi