Bad Gas Cap

Information and questions on GL1100 Goldwings (1980-1983)
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Posts: 144
Joined: Sun Aug 05, 2012 8:46 pm
Location: Milwaukee, Wisconsin
Motorcycle: 1980GL1100 NICE!

Bad Gas Cap

Post by tunaboy » Mon May 06, 2013 8:18 am

Last week I posted a new topic called "Bad Gas". The short version is that the bike would start to miss after I would ride 15-20 miles. I just preformed a bunch of maintenance on the bike and I was testing it without the false tank in place. I cracked open the gas cap and found that I was pulling a vacuum that restricted the fuel flow to the carbs. I love simple fixes to problems. Anyway if you have similar problems try opening the gas cap.

Can I buy an aftermarket gas cap that would work?

What could I soak the original cap in to try to unclog the breather?

I think I can drill a small hole in the OEM cap but we have ethanol here and I like to keep air out.

Thanks, the bike is running great!

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Posts: 25
Joined: Thu Apr 18, 2013 11:36 pm
Location: Lexington, Kentucky
Motorcycle: 1982 GL1100A Aspencade

Re: Bad Gas Cap

Post by Crmpacer » Mon May 06, 2013 8:52 am

I would try soaking your gas cap in either Seafoam or Naptha (found at lowes or homedepot). Naptha is an active ingredient in Seafoam and it acts as a paint thinner/stripper. This is the agent that removes the varnish from your carbs when gas sits too long (30 days or more) in your system. I am not sure how the Naptha will react to your painted gas cap or the rubber seal so be careful and read the directions thoroughly.

I would try this route before drilling any holes. You may also try E-bay to find a used gas cap rather than going with a cheap aftermarket.

Best of luck on your project and thanks for the tip.

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Posts: 181
Joined: Thu Mar 07, 2013 1:54 pm
Location: The Falls, Texas
Motorcycle: 1982 GL1100

Re: Bad Gas Cap

Post by Fulcrum » Mon May 06, 2013 11:22 am

A 50/50 mix of Pine Sol and water are a great cleaning solution. Safe for the rubber parts but will eat paint. Just drop the part in there and let it soak for several hours or overnight. Its cheap and reusable and you don't have to worry about the fumes.

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Posts: 842
Joined: Thu Apr 05, 2012 9:29 am
Location: Winchester, Ontario, Canada
Motorcycle: 1982 1100I, 60A Poorboy, MSD coil

Re: Bad Gas Cap

Post by SteveB123 » Tue May 07, 2013 5:42 pm

Vacuum, eh? I just came from filling up, and mine was under pressure.

That might explain the hydrolock I had to deal with at work!

307km on 16.3 litres.
44 US-MPG, 5.3 L/100km, 53 MPG.

Current:82 GL1100 Interstate, 60 Amp Poorboy, MSD coil
Previous: 93 GSX1100F Katana
82 GL500 Silverwing

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