General Honda GL1000 Troubleshooting Guide

You might consider this item: Randakk’s GL1000 Carb Rebuild Video

Note: You should do a valve adjust and compression test (in that order!) before doing ANY ignition or carb tuning. GL1000s will run poorly when valve lash is not set exactly to spec. Fortunately, valve lash stays “in spec” for a long time once properly set.

Compression Testing 1

Note: Valve timing on a GL1000 is critical. Verify that your cambelts are installed correctly. The “match marks” on the flywheel and the cam pulleys must align perfectly. The GL1000 is an interference design engine. If your belts are off by 1 tooth, your engine will run like crap. If your belts are off by 2 or more teeth, serious engine damage will occur immediately.

 

Note: Keep in mind that all ignition issues must be perfect before carb work is undertaken.

This includes coils, plug wires, plug caps, spark plugs, ballast resistor, breaker points, condenser, ignition advance mechanism, ignition switch, kill switch, main fuse, battery, and all associated wiring harness components.

Ignition performance and timing is critical on GL1000s! Ignition problems often mimic carb problems to an untrained ear.

Potential Ignition Problems:

  • Faulty coil and / or spark plug wires. Check using the method here
  • Dirty, pitted or poorly adjusted points
  • Problem with Ballast Resistor and/or its wiring
  • Spark plug caps…check for excessive resistance (should be about 5,000 ohms max). This should be a secure, screwed – in connection…you shouldn’t be able to easily pull it out of the cap.
  • Problem with wiring from coils to points. Typical problem areas include the junction with the condenser assembly (to the left of the battery) and the “pigtail” which connects to the actual points assembly…very easy to have a short or partial short here.
  • Bad condenser …did you replace? Put the old one back as a test.
  • Weak battery – one classic sign of a weak battery is a tendency for the engine to fire right after you release the starter button.
  • Bad ignition switch, kill switch and / or associated wiring
  • Bad main fuse … these can fail without “blowing”…results in intermittent high resistance to the entire wiring harness.
  • Timing advance mechanism not operating freely.
  • “Dead” cylinder is usually an ignition problem. It can be a carb problem…especially if it is rpm-specific.
  • Faulty stator, rectifier or voltage regulator. GL1000s require full function of the charging system for the ignition to perform as designed. If the charge voltage is substandard, ignition performance will suffer dramatically.
  • Electronic ignitions (like Dyna) are typically powered through the turn signal circuit. If the fuse for this circuit blows for any reason, you will lose your ignition. Yet another reason to carry spare fuses!

Potential Carb Problems:

  • Implement the “off idle” fix (recommended for ’75-’77 models only).
  • A simple problem of carbs out of synchronization. Did you sync properly?
  • Idle speed set too high (at a certain rpm level the ignition advance is activated which can cause an oscillation in idle speed). The correct idle speed is about 950-1000 RPMs (measured with a real tach…not the one on the bike). Some bikes perform better with curb idle of 1050 RPMs or so. Don’t go beyond that idle speed or you will begin to activate the progression circuits in the carbs.
  • Big vacuum leak (did you use new intake o-rings? Did they move out of position?)
  • Check intake rubbers for cracks?
  • Sticky” vacuum throttle slides – did you polish the slides and carb bores?
  • Binding throttle linkage, not enough slack in throttle cables, missing or broken springs in throttle linkages.
  • Binding choke linkage or shafts … choke butterflies are controlled by spring pressure…not direct mechanical connection.

Overly rich mixture for any number of reasons:

  • poor synchronization (causes rich idle and plug fouling at idle due to premature involvement of progression circuits on 1 or more cylinders)
  • worn jet needles or needle jet holders
  • clogged jet holders (emulsion tubes)
  • clogged secondary or primary air jets
  • clogged pilot air jets
  • secondary and primary air jets reversed
  • aftermarket jets poorly sized
  • jets modified by previous “mechanic”
  • deteriorated internal o-rings in carbs
  • bad central plenum gasket
  • float levels too high or poor alignment
  • floats “fouling” on side of the fuel bowl.
  • floats “hanging” due to bent float pivot pins
  • floats “hanging” due to pivot bores on floats that need reaming / alignment
  • defective floats saturated with fuel or other buoyancy problem causing them to ride “low” (rare)
  • dirt in the float needle valve
  • “sticky” throttle vacuum slide(s)
  • leaking float valve assembly (seat and/or needle valve is worn out)
  • aftermarket float needle valve and seat assemblies (notorious for leaking!)
  • idle mixture screws set incorrectly
  • aftermarket jet needles – incorrectly sized
  • dirty or aftermarket air filter
  • deteriorated or missing rubber blanking plugs (over idle jets)
  • aftermarket exhaust
  • high fuel pump pressure
  • faulty carb bowl gasket
  • loose carb-to-plenum bolts

Overly lean mixture for any number of reasons:

  • vacuum leak
  • clogged primary or secondary main fuel jets
  • clogged internal fuel passages
  • clogged idle fuel jets / circuits
  • clogged idle by-pass transfer ports in throttle bore (3 in each carb…under “puck”)
  • clogged idle nozzle jet
  • clogged jet holders (emulsion tubes)
  • secondary and primary air jets reversed
  • aftermarket jets poorly sized
  • jets modified by previous “mechanic”
  • bad air cutoff valve or leak where air cutoff attaches to the plenum
  • clogged vacuum signal port for air cutoff valve (on carb #1)
  • cracked vacuum hose(s)
  • crack in intake rubbers or defective intake o-rings
  • float levels too low…or floats “fouling” on side of the fuel bowl.
  • idle mixture screws set incorrectly
  • “sticky” throttle vacuum slide(s)
  • air filter missing, perforated or aftermarket air filter
  • aftermarket jet needles – incorrectly sized
  • aftermarket exhaust
  • low fuel pump pressure
  • clogged internal fuel screens (at float valve assemblies)
  • clogged external fuel filter
  • defective gas tank cap
  • obstruction in fuel tank pickups
  • dirty or stale fuel
  • loose intake runner clamps
  • loose / missing sync port screws
  • faulty carb bowl gasket
  • exhaust leak
  • “popping” sound can be from sticking intake valve

Fuel Starvation Possibilities (or sometimes dead cylinders that mimic an ignition problem):

  • A blockage inside the fuel tank. Perhaps this has migrated also to the fuel inlet screens under the float valves. If you suspect a tank blockage, siphon most of the fuel from the tank and remove the petcock. Blow compressed air through both the main and reserve circuits. With the fuel cap off, you should hear equal volumes of air rushing through each circuit. If not, that indicates a blockage.
  • Failing fuel pump. As the actuating arm on the pump wears where it meets the eccentric on the right camshaft, pump output and pressure will slowly decline. The Honda manual shows simple tests for volume and pressure minimums. Worn actuating arms can sometimes be reworked by welding on additional metal and grinding to restore proper shape. Such heroics aren’t usually worth the effort as a pump with this issue is already near the end of its useful life.
  • Blocked main fuel filter or fuel inlet screens under the float valves
  • Problem with float valve operation / setting restricting the flow of fuel into carbs. They can be installed incorrectly upside down!
  • Internal fuel circuit blockages
  • Main or idle fuel jet blockages.
  • Internally collapsed fuel line
  • Faulty gas cap restricting venting and causing a pressure vacuum that will prevent fuel flow. Try removing the fuel cap briefly when the problem first appears to diagnose
  • Large external fuel leak (usually obvious!)

Weird loss of power with no other explanation:

  • Collapsed header. These headers are dual-wall construction which is notorious for internal disintegration. This can cause a partial or complete blockage of exhaust gases.
  • Choke linkage / return springs installed incorrectly. It can cause choke to be closed at all times!

REPEAT: ALL IGNITION ISSUES MUST BE PERFECT BEFORE CARB WORK IS UNDERTAKEN. This includes coils, plug wires, plug caps, spark plugs, breaker points, ignition advance mechanism, ignition switch, kill switch, main fuse, battery, and all associated wiring harness components. Ignition timing is critical on GL1000s! Ignition problems often mimic carb problems to an untrained ear.

Key Links: 

If you want to find the best selection online for motorcycle parts, visit our stores below:

www.DimeCityCycles.com | www.Z1Enterprises.com | www.Randakks.com | www.MikesXS.net

Comments

  1. My 1977 Gl1000 idles at around 4k rpms after I rebuilt the carbs.
    Would a carb sync get it down?

  2. Nathan Jones says:

    I have had fouling on #2 plug in less than 20 miles for the two years I’ve been running the bike (’75 engine in a ’78 frame that had MANY PO issues). Finally, after studying all that I could find on the web, including the causes on here, I removed every jet and emulsion tube from that carb. The needle jet holder was seriously wallowed out. I knew the needle had groves around it that were minor, but never inspected the jet (holder?) closely. It wasn’t egged, but was badly worn maybe 20% bigger than stock. Not having a ’75 jet on hand, I replaced it (for now) with the emulsion tube and jet from a ’79. No more fouling!

  3. Carl Nephew says:

    HI all, I just bought a very clean 1975 gl1000 carbs had been overhauled new head gaskets and tune up by a reputable local shop, when I bought it I was aware it wasn’t running correctly, upon further testing I found the bike would be extremely cold blooded then run ok for 2-3 miles then would start losing and gaining power back followed by all of a sudden bogging down and dying with no success on a restart it seems to start and idle fine but bogs down and misses upon throttling it up, any insight?

  4. steve hannis says:

    Hi,
    I have a GL1000 1976 which runs awful!
    The primary chain rattles on tick over which I understand the details of. But would this affect the running?
    Basically it coughs & splutters & struggles to pick up. I’ve had several people look at this bike but nobody can get it right.
    I have cleaned & replaced carb bits, set valves, timing etc but I just can’t get it any better. is there someone in the UK you could suggest?

    • Norton Muzzone says:

      Steve,
      Be sure to go over our troubleshooting guide. For your motorcycle to run as poorly as you have stated there must be something overlooked. Unfortunately, we do not have recommendations for a Gold Wing technical expert in your country. Please visit our website and view the technical blogs that are posted to assist you in your issue.
      Thank you for your inquiry,
      Norton

  5. Gary duwel says:

    Hi…

    After having a starter solenoid problem, I noted a burned connection wire to my regulator. I replaced the regulator and my 79 GL1000 runs great, but my turn signals no longer worked, and when I go above thirty mph, the turn signal buzzer goes on and stays on until I slow below thirty mph…

    Fuses and connections all look good.

    Is there a place you recommend that I should start to get to the heart of my problem?

    Thank in advance and thank you for having an excellent blog..

    Gary

    • I would replace the flasher and turn signal buzzer and go from there.

      • Gary duwel says:

        I replaced the flasher and the turn signal buzzer.

        The turn signals work, but the buzzer beeps off and on as soon as the ignition is turned on and with the turn signal switch in the neutral position.

        • Sounds like a “ghost feed” issue with the turn signal switch.

          • Gary duwel says:

            I dismantled, inspected and thoroughly cleaned, added a dab of Vaseline, and reassembled the turn signal switch. There were no visible issues and it appears to be in good working order.
            How do I check for a “ghost feed”?

          • No fix. Just replace the switch.

  6. Hello, I just came upon a 1978 GL1000 that has been siiting in storage for twenty-five years. Got it for a good price. Looking forward to this being a project restore. It ran before it was parked. Would like to see if it will start before an overhaul. Any first step suggestions would be appreciated.

    David in Florida

  7. I have a 79′ GL1000, its been sitting for about 8 months, I got it running again( new oil, fuel, charged battery)
    but it seems to idle low so I turn the fly open but once the bike is up to normal temp it starts to idle high ~1200RPM. what do you think?

  8. Joe Martin says:

    I’ve had lean idle issues with some my gl1000s. I think I have figured out something I was doing wrong. Being afraid to strip the carb bowl screws I was leaving them snug. With new gaskets they need to be relatively tight to seal the idle passages in the front of the carb bowl gasket areas. Have yet to bolt my present set of carbs back on to see if the lean idle is corrected.

  9. It took 1 and half year to figure this out

    On the dutch goldwing forum we had a member with the problem that with a carbtune meter (for synchronizing) one cylinder was losing the vacuum :https://www.youtube.com/watch?v=dZlYf-y2qGM

    After a very, very long search, and testing en and replacing almost everything with the suggestions of the members, we suspected that is was not a leak, but pressure that was causing this. https://www.youtube.com/watch?v=5PB8vGYdDvU&feature=player_embedded

    Finally he discovered, that it was the (bobine) coil which caused this, although only on one cylinder. After replacing the coil the problem was fixed.

  10. William Grant says:

    I have a 79 Gl1000 w 26,000 miles. I replaced brake lines, external oil seals, belts, fluids, complete ignition from coils down including dynacoil electronic ignition. set timing adjusted valves. found the left front header had 90% blockage, replaced header, It no longer pops or backfires through the carb but the left front cylender is dead . ie loads of spark but no gasoline. The carbs were rebuilt by the former owner with all japanese parts. Any suggestions? I donrt know is skill level.

  11. Carburator clean is not enough

    When I bought a second Gl1000K3 it was meant as donor for spare parts, but soon I found it a waste of a almost good machine. So I started to correct things. The bike ran good, but was lousy to start.
    With Randakks’ tech tips I found that an ignition cable was broken, after fixing it I decided to clean the carburetors. After that there was a petrol leakage to the air intake and the cylinders were overflown. It took me some time to figure out wat was happening. When tested it seems that all float needle valves were operating correct and the level was oke too. I realized that there were leaking petrol gaskets in the plenium. Further inspection showed that the butterfly axes were worn considerable.

    So I weighted my options and found a better replacement with the same number 755 B.
    This one had the mixed up problem (secondary and primary air jets reversed) and after a thorough cleaning job, the bike ran awful. A lot of back fire and lousy below 3000 rpm. Ignition rechecked, new point, carburetors cleaned again each jet mechanically cleaned, brake cleaner and a lot of compressed air but nothing seems to help. I was really out of options and ideas. After reading a lot about this carburetors I started to understand the functions of the different circuits in the carburetors. We miss these basic diagrams on Randakks site, but I found this paper from Mike Nixon very helpful to understand the inner workings. http://www.motorcycleproject.com/text/keihin_idle_circuits_white_paper.swf

    I also read a German paper vergasserkunde. In the mean time I drove my classic BMW R100 RT, but wanted the naked GL1000 K3 operational in the spring again.

    As a desperate measure I filled the tank and added Wynns carburetor clean and let the motor run for a while. After that I put it aside until spring. To my surprise the GL started and ran much better in the spring, some sort of self-reparation, but it seems obvious that the carburetors were still not clean enough.

    All tough Randakk is against submerged cleaning, i decided to give it a try. As I released that oxidation in tiny channels could also causes (partial) blocking. I found a German product (tickopur r33) which was slightly etching and use the water solution mix in my ultrasonic cleaner .This tickopur product is widely used for carburetor cleaning in Europe, and i read good reviews about its working.
    That finally did the trick, and after applying the idle of glich https://www.randakksblog.com/how-to-cure-off-idle-flat-spot/ I have now a almost 40 year old machine, that runs better than I can remember of any GL1000K3 (1978).

  12. owen Taylor says:

    Hi I have had a 1976 gold wing GL 1000 for 10 years now it has been a great bike( with the usual repairs os an old bike) I had it on start up warming up nicely for about 8 min. it shut down all by its self Now I have no power no ign or any wear. The battery is new all fuse blocks are good wiring looks O/K the only indicator was a hot wire ( temp) from the solenoid I have not taken apart the wire harness yet Ign switch looks O/K any ideas?
    On my way out for a 10 day trip for my 60th!! Help!

  13. Ken Kauffmann says:

    Thanks for this fantastic site. I had installed some reproduction Helmet locks which required me to take the seat off, and reinstall it. I checked the turn signals and noticed that the left turn was flaky. I removed the seat, checked all the connections, and reinstalled. The turn signals worked.

    I then took off for what was going to be a beautiful morning ride. Not 1000 feet from my home, the engine died. It would crank, but would not catch. I checked fuel, etc., but wound up having to push the bike home.

    I turned to your site, wondering what the procedure was going to be to troubleshoot this problem. And there, right on the first page: “Electronic ignitions (like Dyna) are typically powered through the turn signal circuit. If the fuse for this circuit blows for any reason, you will lose your ignition. Yet another reason to carry spare fuses!”. I ran down to the garage, and checked to see if the turn signals worked: Nothing! I checked the Horn/Turn signal fuse: Blown.

    When I had reinstalled the seat, I had pinched the rear left turn signal wire. When I sat on the seat, I must have created a short. When I used the Left turn signal, I had blown the fuse, and lost the Dyna ignition. ( It looks like i fried the turn signal flasher as well – thanks for recommending the 522 flasher as a temporary replacement until the OEM flasher arrives. ) I am back on the road.

    Thanks for saving me hours of diagnostics, and for maintaining this site.

    Ken

  14. my 1975 GL acts like it is flooding will run great with petcock closed. open it starts to bog down like flooding. close petcock the bike will run smoothly after a moment or so.
    going down the road will run great a mile or two with petcock closed open start to bog
    again close smooth out run great another mile or two. any sugestions what to look for?
    I rebuilt the carbs several years ago. the bike has run great until this started the other day.

  15. Bill R. says:

    I have an issue with my 76LTD that has me stumped. Overall this is the BEST running GL1000 I have ever owned or ridden, but after riding or rev-ing the engine, it will sometimes drop the RPMs to below normal idle and then recover, and sometimes it will stall. If I attempt to bring it up with the throttle it will stall most of the time. It has the correct carb.s for the LTD with the Randakk’s master kit parts installed, with the air jets from a 77 (the only non-stock thing about this bike, and IMHO not perfect but a great work-around to your off-idle fix). Cam belts on perfect, carb.s sync-ed, valves set, all new hoses, timing is spot on for both gap and time, and all done in the correct order. One note is that I had to do BOTH points with the split timing.

    Please forgive me if you have already posted about this issue, but I have not been able to find it on your site. I’m no where near a GL1000 novice, as I have owned/restored/and worked on these bikes for about 30 years.

    I’ve been using your parts for years on all my Wings, and tell everyone to use them as well. Thank you again for providing fantastic parts!

  16. Brian Fargher says:

    I have a 1977 GL1000, I have replaced the carbs with a single carb and manifold, I have replaced the starter switch, new battery, solenoid, points, condenser, main fuse. Checked the timing, timing belt, all perfect, but can not get the bike to run after it falls below 2000 rpm, it’s just like I turn the ignition off. What else can I do to fix this problem?

  17. Pete Sweeney says:

    Hi,
    I purchased a good replacement cam belt for my ’75 GL1000 from NAPA, as per your substitution list. Recently, I have aquired a GL1200 job that also needs belts – I noticed that Honda’s p/n is different for this belt. Is there also a good NAPA p/n for this belt too, or are the GL1000 and GL1200 really the same?
    Thank you,
    Pete

  18. every so often i’ll press my starter and the starter motor “whizzes” but doesnt engage what could this be please, someone local suggested a weak battery?

Trackbacks

  1. […] type of carburetion problem that causes over-richness can reduce fuel mileage. See the chart here (written for GL1000, but most applies to any bike of similar […]

  2. […] a list of the typical reasons for lean and rich […]

  3. […] type of carburetion problem that causes over-richness can reduce fuel mileage. See the chart here (written for GL1000, but most applies to any bike of similar […]

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