rough idle


Information and questions on GL1200 Goldwings (1984-1987)
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rcmanwood
Posts: 11
Joined: Fri Jan 27, 2012 11:38 pm
Location: Russellville, Arkansas
Motorcycle: 1985 honda aspencade
gl1200

rough idle

Postby rcmanwood » Sat Jun 15, 2013 9:24 am



I have a gl1200 asp. 1985 mod. missing at idle and stumbles at takeoff. I can pull the plug wires on right bank and nothing happens. I pull a wire on the left bank and it dies with either plug. Any help out there. What readings should I get on the plug wires ect. Any help would really be appreciated.



User avatar
virgilmobile
Posts: 7659
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: rough idle

Postby virgilmobile » Mon Jun 17, 2013 3:47 pm

From a cold engine start and just idling(no reving it up) for 10 seconds,each exhaust header should be equally warm..If not and the bike runs OK after take off,I'd be looking into fuel delivery problems...
The ignition system is split into 2 parts...one coil fires the front and the other fires the rear.
Both cylinders not firing on one side eliminates the ignition system and leads to either compression or fuel...if it runs OK above 1500 rpm,the likleyhood of compression problems goes down and leaves the carbs slow speed fuel circuit (plugged slow speed jets)or a bad sync job.....

dkcloud
Posts: 21
Joined: Fri Oct 15, 2010 6:04 pm
Location: corpus christi texas
Motorcycle: 1984 GL1200 Interstate

Re: rough idle

Postby dkcloud » Sat Jun 29, 2013 4:55 pm

You pulled the plug wires on one side and nothing happens. :?
Maybe the miss on that side, check your ignition wiring first

I had the exact problem you have.
1. I pulled the plugs and read them
2. I connected the plugs to the spark plug boots and verified spark
I hit the start button and I noticed that I was getting a very weak spark on all 4 plugs
( I have Dyna coils on my bike)
I checked the spark directly out of the coils and it was HUGE.
I found 2 bad spark plug boots (caps) on my ’84 1200
This is how my ignition system was set up.
The bike uses stranded wire, resistor spark plugs And the spark plug boots "caps" also have resistors in them.
The resistance in each boot is 5k ohms (5 thousand ohms)
The spark plug resistance is around 4k ohms on each plug.
This puts the total resistance to 9-10k ohms per cyl.
This resistance is for radio suppression and is not really needed.
If the bike lacks power or misses, check the resistance in the spark plug caps.
I just replaced my wire set with Accel yellow jacket universal set from Advance Auto, got rid of the stock spark plug caps and went to standard rubber boots on the plugs.
I went to NGK non resistor plugs, same heat range
The reason I did this was to improve the spark to the plugs

End result: quick start, miss gone and increased idle speed.
I am putting the bike back together to take a test ride

dkcloud
Posts: 21
Joined: Fri Oct 15, 2010 6:04 pm
Location: corpus christi texas
Motorcycle: 1984 GL1200 Interstate

Re: rough idle

Postby dkcloud » Sat Jun 29, 2013 9:40 pm

PS:
I just did a test ride and I did get some popping on the AM radio band and a little crackling on the FM band by removing all resistance out of the ignition wires.
The idle was so smooth I thought I was on a different bike.
My problem was bad spark plug caps (boots) that caused my bike to miss and not idle.
My next step is to replace the non-resistor plugs with resistor plugs and see the effects on the radio.

rcmanwood
Posts: 11
Joined: Fri Jan 27, 2012 11:38 pm
Location: Russellville, Arkansas
Motorcycle: 1985 honda aspencade
gl1200

Re: rough idle

Postby rcmanwood » Sun Jul 07, 2013 8:10 pm

Thank everyone for there input. My trouble was two broken o rings on the two right intake tubes. Replaced them and it runs fine. Thanks again for the info.




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