Technical Rochester 2g leaking gas

I'm having a problem with my center carb. After driving the car, even just around the block I get gas leaking. It appears to be coming from the gasket between the base and the body. It stops dripping after about 10 minutes. I did take the top off and lower the float from .775"to .835" but it made no difference. As I said I only drove around the block after the adjustment so I don't think heat is the issue right now. The two outer carbs are not giving me any problems. Any suggestions are appreciated.


Phil

 

Either fuel pressure or needle is stuck or dirt keeping it from closing. Since just one carb I suspect the needle. I'd clean the needle, seat, and fuel inlet and give it a try. Worse case you'll need a kit and rebuild it.

 

Check with a straight edge to see if the top is warped.

 

This, from the "troubleshooting" section of my website:

https://www.thecarburetorshop.com/Troubleshooting.htm#Fuelleak

Jon

 

Like others have mentioned, double check fuel pressure, needle, and seat.

Take a look at the bottom of the body- there are several small holes that were soldered closed/leaded shut from the factory as part of the manufacturing process. That could be a leak area.

Also, check to make sure you have the correct gasket between body and baseplate. I made that mistake before, although that would present itself as a vacuum leak.

 

needle and seat. I replaced mine with what's called the "Daytona" valve sold separately-not sure by who now but you could find a supplier on the net. They work great in conjunction with an accurate fuel pressure regulator-set at around 3 psi. Note I said accurate, not using their built in dial.

 

It looks like I found my leak, it's been sitting since Wednesday and the manifold is completely dry. There was a small crack in one of the plugs that the manufacturer uses to seal the end of the passage under the power valve after they drill it. I was going to replace the body with a spare I had. Once I had it on the bench I poured some thinner in the bowl and could finally see the leak. I cleaned it up and put a dash of JB weld, let it sit overnight and tested it with thinner again. I put it back together, went for a test drive. It's never behaved this well.

Phil

 

Cool, now you can go have some fun with it.

 

Let us know if this is a permanent repair. JB Weld doesn't play well with the ethanol in gasoline. The JB Weld turns soft and will degrade. I usually drill, tap, and install a set screw with red loctite to repair this type of leak.

 

Thanks, I will keep an eye on it. Now that I know where to look it will be easy to spot. I also always use ethanol free premium.

Phil