Idle issues


Information and questions on GL1500 Goldwings (1988-2000)
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BIGBopper1956
Posts: 9
Joined: Fri Apr 12, 2019 12:40 am
Location: Palm Springs, CA
Motorcycle: 1993 GL 1500 Aspencade
1999 GL 1500 Valkyrie Interstate
1999 GL 1500 Valkyrie Tour
1999 GL 1500 Valkyrie Standard
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Idle issues

Post by BIGBopper1956 »



1993 GL 1500 Aspencade 43,000 miles stored eight years in a climate controlled garage Palm Springs, CA. Pulled and rebuilt carbs and still had idle issues. Finally took to a shop where they discovered bad intake boots, synced and adjusted carbs and everything seemed good when picked up. Had a bad gas smell and discovered leaking petcock. Rebuilt along with replacing the fuel filter (was bad) and took it for a ride. Seemed fine for a short time 3-4 days 10-15 miles per day. Was having clutch slippage (air in lines and Master and Slave cylinder rebuild) seemed to cure the issue. Now bike is not idling correctly Set to 900 and it is fluctuating 800-1000. With choke on slightly seems to do a little better. Drove it and noticed when letting off the throttle bike nearly dies. Drops to 200-300 rpm and then climbs back to 800-1000. Choke on or off no difference. Sitting in garage not under any load still nearly dies when letting off throttle. Also acts like starving for gas when in 3, 4, 5 gears and trying to accelerate. Not sure what happened but it did seem sudden.

Not thrilled about pulling carbs again, but willing to do whatever is necessary to finish this up and ride with confidence. Am I looking at vacuum, or something along a different train of thought? All tupperware is back off and down to looking at carbs again. Thanks in advance for any advice,

BIGBopper


BIG Bopper
Tim Bannister

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ct1500
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Joined: Wed Nov 10, 2010 8:09 pm
Location: Glastonbury,CT
Motorcycle: 1988 GL1500
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Re: Idle issues

Post by ct1500 »

You have to take the fuel system as a whole. What is the fuel pump pressure, can the petcock pass vacuum/flow checks, are all vacuum lines routed correctly, does it have vacuum leaks? Running problems can usually be traced back to the carburetors and always use OEM Honda parts.
Your idle surge sounds like it is lean, your RPM dropping after revving sounds rich like float height setting issues, your lack of top end power sounds like petcock/fuel pump issues. There is no one part replacement to cure running issues, things need to be tested while running prior to removing components which helps narrow down specific faults so they can be looked at on disassembly. Lean idle? Check for vacuum leaks first so one can concentrate on carb idle circuit. Poor high speed performance? Check for proper fuel delivery to carb first then concentrate on main and secondary main circuits of carb. You also have Air Jet Controller and Shot Air system performance to check before diving in. Having fouled spark plugs or broken down ignition wires will affect the end result, lots to consider to get it done right the first time. :)
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BIGBopper1956
Posts: 9
Joined: Fri Apr 12, 2019 12:40 am
Location: Palm Springs, CA
Motorcycle: 1993 GL 1500 Aspencade
1999 GL 1500 Valkyrie Interstate
1999 GL 1500 Valkyrie Tour
1999 GL 1500 Valkyrie Standard
Contact:

Re: Idle issues

Post by BIGBopper1956 »

Well after reading your reply, I may want to shoot myself!! Only kidding, but it sounds extremely complicated. Am I correct that vacuum is where to start first? Whatever I do it looks like the carbs will be coming off again. Just not excited after spending a fair amount of money at a shop.
BIG Bopper
Tim Bannister

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