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Discussion Topic:
'49 merc gas leak at carb.
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janman33 |
05-05-2011 @ 6:36 AM
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Member
Posts: 30
Joined: Oct 2009
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I have a '49 merc. and cannot seem to stop the slight gas seep were the fitting screws into the bottom of the carb, from the fuel pump. Is this a cronic problem with these carbs? How do i stop the leak? the fittings on both ends look good and they are tight. Thank you
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supereal |
05-05-2011 @ 10:42 AM
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Senior
Posts: 6819
Joined: Oct 2009
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When a fuel fitting leaks, it is usually caused by the distortion of the ferrule on the end of the line by overtightening. Once the ferrule is damaged, no amount of tightening will stop the seepage. Be careful that you don't damage your concentic carb. I don't recall if the seat is in a separate fitting. If so, it may be replaceable. Don't attempt to use Teflon tape, or other sealant, as it usually causes float needle problems.
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janman33 |
05-05-2011 @ 4:55 PM
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Member
Posts: 30
Joined: Oct 2009
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Thank you for the input,Supereal
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TomO |
05-07-2011 @ 6:49 AM
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Senior
Posts: 7250
Joined: Oct 2009
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This seems to be a common problem. A fellow member of my RG had a brass bushing fitted to his carburetor to solve the problem. It seems like the threads in the pot metal become worn from overtightening the brass fitting, so the the gasket for the brass inlet fitting cannot seal. By putting a brass insert with new threads, the fitting can be tightened enough to compress the gasket so it can provide a seal. When we were trying to solve his problem, I inspected several carburetors at swap meets and all of them showed signs of leakage at the fitting.
Tom
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ken ct. |
12-01-2011 @ 4:50 PM
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Senior
Posts: 1513
Joined: Jan 2010
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49-51 merc carbs do not use a ferrel type gas line fitting it is a double flares tube and uses an inverted flare type fitting for the line connection. Some also came thru with an 1/8" PT hole in the carb. ken ct.
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supereal |
12-01-2011 @ 5:48 PM
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Senior
Posts: 6819
Joined: Oct 2009
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Ken is right, but because of leakage problems with the concentric carb, many were changed to the tried and true ferrule connectors. You need to a determine which you have, and renew the connector and/or the line from the pump to the carb.
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