86 GL1200 runs rough after warmed up

Information and questions on GL1200 Goldwings (1984-1987)
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Posts: 1
Joined: Sun Sep 12, 2010 6:13 pm
Location: Alvin, TX
Motorcycle: 1986 GL1200 Goldwing Interstate
1991 1500 Interstate

86 GL1200 runs rough after warmed up

Post by wotscott » Sun Sep 12, 2010 6:59 pm

I just inherited 2 Goldwings and I'm trying to get the 86 GL1200 GOING. It was sitting for 3 years, so of course the carbs were clogged up. I rebuilt all 4 carbs and now it runs, but after it runs for a few minutes it starts to run rough and backfires. After about 5 minutes it ran like it was running on 2 cylinders. I've been a auto mechanic for over twenty years and I pulled off a plug wire one at a time and I found that number 4 cylinder was the only keeping the engine running! Any of the other wires when pulled off, the engine just stumbled a little bit and I could keep the engine still running while opening up the throttle.
Now, I did not replace the carb slides with the diaphrams on them. They were in great shape. I did get all new jets, floats, and gaskets for the carbs.
These bikes were my Dads and he had a accident on the 91 goldwing and I want to fix it up, after I get this one running and sold. This bike also has a sidecar attached to it!

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Re: 86 GL1200 runs rough after warmed up

Post by WingAdmin » Mon Sep 13, 2010 10:53 am

If it sits for a while and then starts up fine again (only to die a few minutes later), I'd look first at fuel - fuel filter, carb screens...if it sat for that long, there's a good chance there may be corrosion inside the tank, which will clog everything downstream.

Also have a look at the fuel cap. If the vent in it is faulty, a vacuum can build up in the tank which will stop the fuel flowing after a few minutes.

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