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gas exaust smell

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PHAT69AMX View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote PHAT69AMX Quote  Post ReplyReply Direct Link To This Post Posted: Apr/16/2018 at 10:13pm
I'll contradict myself, Jetting could cause the smell, unburned gas in exhaust pipes..
Revised previous post...
Exhaust pipes and gas tank, proximity can "boil the tank", another "new fuel" possibility...
Once when "in-between" getting an exhaust finished, drove mine awhile with half-pipes,
no tailpipes, exhaust ended at rear end, and yep, it would boil the gas tank, lol ! 
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mixed up View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mixed up Quote  Post ReplyReply Direct Link To This Post Posted: Apr/17/2018 at 2:16am
you say the carb drains down while setting after a long drive park the car t hen look in the carb see if its dripping into the intake could have 1 a sunken float or 2 high float level causing the carb to siphon the fuel out of the bowls or bad needles & seats
69 amx 290 auto
65 220 290 4spd
80 ford fairmont
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Red Devil View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Red Devil Quote  Post ReplyReply Direct Link To This Post Posted: Apr/17/2018 at 7:43am
If your '68 has no charcoal canister to store fumes from the fuel tank and carburetor bowl vents, and both just vent to atmosphere, it will be pretty tough to control fuel smell from normal evaporation in an enclosed garage.

Suggest add a charcoal canister with appropriate connections to tank and carb like later models, if possible. 

Hope this helps, RD 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken_Parkman Quote  Post ReplyReply Direct Link To This Post Posted: Apr/17/2018 at 11:35am
Yep - old cars stink. We are spoiled by newer stuff.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote akimmet Quote  Post ReplyReply Direct Link To This Post Posted: Apr/17/2018 at 12:28pm
A little bit of gas smell is normal, but a lot of gas smell indicates a leak, pressure build up, or running extremely rich.

You seem to have checked most of the obvious stuff already.
Gas smell from the exhaust is almost always from the idle mix being set extremely rich.

Try tuning your idle mix with a vacuum gauge, it is far more accurate than tuning by ear.

It isn't uncommon for some carburetors to have ruined idle mix screws from people over-torquing them. Take one out and check for flat spots on the taper of the needle.

Float mis-adjustment, can cause an extremely rich condition as well.

The carburetor bowls being empty after sitting a week is somewhat normal for an aftermarket carburetor. Modern gas simply evaporates far more easily.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ditdit Quote  Post ReplyReply Direct Link To This Post Posted: Apr/18/2018 at 2:37am
thank you all for the sugestions 
1968 AMX 401/727
1984 Eagle 4.0 org owner
1988 Eagle (time machine)
1980 Jeep J10
1977 Hornet AMX (Green)(sold)
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RUMBLR Quote  Post ReplyReply Direct Link To This Post Posted: Apr/18/2018 at 6:02am
Id say more to do with fuel tank venting than a carb issue.

Old rubber fuel lines could also be an issue.

PTFE fuel lines may assist, and a filter of some sort or carbon canister on the vent line.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: Apr/18/2018 at 10:33am
Originally posted by Ken_Parkman Ken_Parkman wrote:

Yep - old cars stink. We are spoiled by newer stuff.
true
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