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Discussion Starter #1
So I'm 18 years old abd heading off to college this fall. I got my motorcycle liscense and picked up 1982 gl500 back in December of 2019 and bought it to have a bike in college as i have been riding dirt bike since i was a little kid and wanted a street bike. I completely rebuilt the motor. Only left in the crank and cam shaft. The bike now idles ok, just needs idle turned up. But when i drive it it wont go over 5k rpm and only runs on the left cylinder over 5k rpm. I've read some about the ATU possibly causing that. I've cleaned and rejetted the carbs. I've also tried 2 different sets of stock carbs. I need help. I've rebuilt a couple dirt bikes and tons of snowmobiles but have never had an engine give me troubles like this thing has. Thank you.
 

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Have you checked the pulse generators. See section 17 of FSM (link in my sig line.) should read 530 ohms +/- 50 ohm.
Did you reset the air gap on the ATU coils during install? Air gap .45-.65mm or .018- .026in
 

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Discussion Starter #4
Take it up the street with the airfilter removed.

Check the airbox for vermin.
I have it jetted for pid filters and have them on. So no air box. Im doing a lazy cafe racer basically. Don't have time for front end swap but it doesnt have an air box and is jetted for different exhaust too
 

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Discussion Starter #5
Have you checked the pulse generators. See section 17 of FSM (link in my sig line.) should read 530 ohms +/- 50 ohm.
Did you reset the air gap on the ATU coils during install? Air gap .45-.65mm or .018- .026in
Thank you I will try that when i get home from work tonight.
 

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Discussion Starter #9
Yes, i have ran it down the street with no air filter
 

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Discussion Starter #11
Could it be the ATU getting stuck and not advancing the timing as rpm goes up?
 

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Discussion Starter #12
Thank you for replying so fast. How do you do a timing light test on these bikes? Never done one.
 

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You need a bright light- at least a xenon.

The timing is checked through the round cover at the rear right of the motor on the back cover.

Drain .5 litre of oil and put bike on sidestand.

The timing marks show in the hole. You would be looking for LF and RF at idle and should see it move up to between the two full advance lines as the revs are increased. If it stays at baseline LF/RF the ATU aint ATUing.
 

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Discussion Starter #14
No difference?

If you put a timing light on it you can see if the ATU is working.
It made no difference with air filters on or off. But it also seemed like it ran fine in neutral. But in gear at around 5k rpm the right cylinder quits running
 

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Some of the fellers here know the 82 ignition system better than me {it's the only system I don't personally run} and can maybe give you advice on the possible modes of failure of the spark units and pulse generators.

This just based on one cylinder entirely dropping out.

But in the case of the spark units you can swap those from side to side and see if the fault follows. Ditto plugs, plug caps and ignition coils.

If you rule those out by swapping, test the advance and resistance check the pulse generators you will either have found the fault or ruled out most possible ignition faults.
 

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Discussion Starter #16
You need a bright light- at least a xenon.

The timing is checked through the round cover at the rear right of the motor on the back cover.

Drain .5 litre of oil and put bike on sidestand.

The timing marks show in the hole. You would be looking for LF and RF at idle and should see it move up to between the two full advance lines as the revs are increased. If it stays at baseline LF/RF the ATU aint ATUing.
Thank you
 

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I would check your plug cap resistance. You may have a faulty cap that goes open under load. Any cracking of the plastic is not a good sign should have 5k ohm resistance. There is the brass rod mod that works well using resistor plugs. Also check ign coils for any cracking. Test procedure is in the FSM as well.
 

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Discussion Starter #18
I would check your plug cap resistance. You may have a faulty cap that goes open under load. Any cracking of the plastic is not a good sign should have 5k ohm resistance. There is the brass rod mod that works well using resistor plugs. Also check ign coils for any cracking. Test procedure is in the FSM as well.
It has different spark plugs as it has aftermarket coil and plug wires
 

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Discussion Starter #20
Id have to look but im at work. It essentially has stock plugs with the caps on them. And it has a nology profire coil i think
 
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