79 gl1000 engine revs itself up to 3000 rpm and rough idle


Information and questions on GL1000 Goldwings (1975-1979)
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arcross
Posts: 9
Joined: Tue Sep 09, 2014 2:07 pm
Location: Vancouver, British Columbia, Canada
Motorcycle: 1979 gl1100

79 gl1000 engine revs itself up to 3000 rpm and rough idle

Post by arcross »



Hey hope someone can help me out I recently got my 79 gl1000 and notice that periodically when stop at light or couple times when cruising along engine gets stuck at 3000 rpm drops back down if I wait it out or as soon as I hit the shifter what could be causing this the guy I got it from told me about rough idle said the carbs need to be balanced which I'm planning to do soon as I get a manometer or make one could it be the carbs causing it to rev up aswell thanks in advance for any thoughts or info you can share with me


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virgilmobile
Posts: 9100
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: 79 gl1000 engine revs itself up to 3000 rpm and rough id

Post by virgilmobile »

Check for sticking slides, vacuum leaks at the head, throttle return spring not set right(not closing the throttle plates.
Its the spring at the back center of the carb...held by a 6mm bolt.
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Aaron Kevern
Posts: 8
Joined: Mon Oct 28, 2019 6:24 pm
Location: Muskegon, Michigan, U.S.
Motorcycle: 1976 GL1000

Re: 79 gl1000 engine revs itself up to 3000 rpm and rough idle

Post by Aaron Kevern »

My '76 GL1000 does the same thing. I have Fresh Rebuilt and Tuned Carbs. Brand New Lines and all. New Choke and Throttle Cable Installed. New Fuel Pump, New Fuel Lines. Next is the Clutch and Trans Gears....it will Neutralize out of 1st Gear if I'm hard on it... But my bike STILL does the same thing, I stop at a Stop Sign, or Stop Light, it Holds idle at 3,000 RPM's. I play with my Clutch to SOMETIMES get it to idle back down to the Proper 950 RPM's. But sometimes it will just die instead of falling back down to 950 RPM's.....what could this be? I'm almost 90% Certain it has to be something in the Clutch/Trans causing this....? Did you ever figure out Your issue, Arcross?
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ohiobobcat
Posts: 8
Joined: Sun Sep 29, 2013 2:33 pm
Location: Athens, Ohio
Motorcycle: 1977 GL1000

Re: 79 gl1000 engine revs itself up to 3000 rpm and rough idle

Post by ohiobobcat »

I had the same problem at one point. It ended up being a slide sticking in one of the carburetors. I could play with the clutch to slow the engine down far enough that the slide dropped, dropping the idle speed. I was able to see in the intake with a small camera and tell which slide was sticking. I ended pulling the entire set off and used a shopvac to pull air through the runner on each carb while moving the throttle. This showed me which ones were sticking, as well as not moving smoothly. Make sure you empty the fuel from the bowls before you start pulling atomized fuel into the vacuum!
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Aaron Kevern
Posts: 8
Joined: Mon Oct 28, 2019 6:24 pm
Location: Muskegon, Michigan, U.S.
Motorcycle: 1976 GL1000

Re: 79 gl1000 engine revs itself up to 3000 rpm and rough idle

Post by Aaron Kevern »

Okay thank you! Looks like I'll be pulling the carbs back off to check the slides👍
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ohiobobcat
Posts: 8
Joined: Sun Sep 29, 2013 2:33 pm
Location: Athens, Ohio
Motorcycle: 1977 GL1000

Re: 79 gl1000 engine revs itself up to 3000 rpm and rough idle

Post by ohiobobcat »

You also mentioned that it was recently tuned. Were the carbs synced at the same time? If you have one throttle blade too far open compared to the rest of them the engine will take off like you're describing too.
Ralf_CT
Posts: 20
Joined: Tue Apr 04, 2017 10:24 am
Location: Cape Town, South Africa
Motorcycle: 2014 Honda PCX150. Owned an '81 400 Hawk, '81 Silver Wing Interstate, '81 Gold Wing GL1100 Interstate from '90-'91, stopped riding in 1994, back in saddle since 2014. Keen to get a GL1500 or GL1800.

Re: 79 gl1000 engine revs itself up to 3000 rpm and rough idle

Post by Ralf_CT »

Play on your throttle shaft will also affect your idle, if excessive, the action of the return spring may even raise it to 3,000 RPM as it tilts the shaft and opens the throttle flap. Also check for vacuum leaks.


Ex GL1100 Interstate rider. Aspiring GL1500/1800 rider.
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