82 Goldwing gas milege

[eldirtyuno]

Hey, I was wondering if any of you guys know what to check if gas milege is really low on an 82 GL1100. I had the carbs rebuilt and Sincronized at a honda shop by a older mechanic so I feel they were done right. Valves, timing, ETC.
Thanks

[BuzZz]

I'd start by checking the easy, obvious things.

Does the bike roll freely. Could be a dragging brake or bad wheel bearings, hopefully not a binding in the shaft drive someplace.... check tire pressure, just cause your down there anyways.

Make sure there is no restrictions in the intake (dirty or incorrectly installed air filter) or the exhaust (broken baffles or other cloggage in the pipes)

Does the bike run the about the same as always? Still got good power, ect? All the spark plugs are good and the bike is firing on all cylinders?

[eldirtyuno]

I have been through the brakes and the bike really rolls smoothly. I installed new plug wires and plugs. I replaced the thermostat. I have changed the drive oil and lubed the drive shaft. Routine oil changes. Tire pressure is optimum I believe at 28 front and 35 rear. The bike fires up everytime and runs well but after it gets hot it idles at about 1500rpms, intead of the 900 it pulls in the begining. That makes me think something is up. Also, The right two cylinder plugs usually get a good coating of soot after a few hundred miles. Carbon build up I guess. Can that be a head or valve problem? Is there an easy way to determine how much spark the plugs are actually getting? (For coil replacement or firing system). Thanks for the help in advance.
John

[BuzZz]

Black plugs, poor mileage, raised idle.... kinda sounds like rich jetting in one or more carbs.

You might want to contact the shop that did your carbs and quiz them up on it. They should have a look and fix anything they might have messed with for nothing. They should........

Sounds like you covered most other things it could be.