Gas in exhaust

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bthieson

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I've had this problem with unburned gas coming out my exhaust. If you have any suggestions on what might be the problem, I would be glad to hear it. I thought it was the carb, but it ended up not being the case.
 
What is your carb type?

sounds like a heavy flot, flot set to high, or if a holley a very bad leaking power valve?
 
I actually don't even know what kind of carb it is. It's the classic single barrel that came with the 225 slant six. I'm positive it's gas, the exhaust just reaks of it. If I'm stopped at a light, all I can smell is gas.
 
timing & ignition componets. IE poor plugs, ill timed, bad gas, poor plugs, air leaks etc...
 
rumblefish360 said:
timing & ignition componets. IE poor plugs, ill timed, bad gas, poor plugs, air leaks etc...
Click to expand...
Yeah, I've been thinking plugs for a while now actually. I haven't replaced them since I bought the thing 5 years ago, and I have no idea how old they are. It might do the trick.
 
If you can smell unburnt fuel in the exh, you may have more issues. But really, if you smell it at a light, and the exh system is in good shape, it may be a leak elsewhere. A good exh you shouldnt smell anything, as it wont enter the vehicle. If you can smell raw fuel, look for a leak possibly at the tank, or in the feed line from the tank.
 
The gas is definitely coming out my exhaust pipes. I put a new manifold, and whole exhaust system in 2 summers ago. I had the same problem before I did that. It's very frustrating, especially with the gas prices where they are this summer.

When I stop, the exhaust fumes just float around and I can smell it. I'm certain the smell isn't coming from anywhere else.
 
A sure fire way of finding out where the gas smell is coming from is to park the car on some fairly fresh asphalt for a couple of hours, with a full gas tank. If you can find a spot on the asphalt that is starting to eat away look straight up from the spot and that is where the gas smell is coming from. It may travel a little ways away, but it will be close. If there is no spot, start the car and let it idle for a few minutes. If the unburnt fuel is coming out the exhaust, then there will be a spot under the end of the tailpipe.

Jack
 
If its coming from the exhaust pipe - My guess is a stuck carb float - or float set too high, choke stuck, or ignition issues. Make sure if its stock electronic dist that the reluctor gap is set properly.
 
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