Quick question, I'm putting a new fuel line shut off valve on, do I need to seal the threads going into the carb?
Some times it doesn't need it. It depends on the amount of wear on the carb inlet threads. You won't know until you try it out. There is a perimitex sealant that is fuel resistant you can try Dab on carb threads and stuff treads and put together. Needs 24 hours for cure I think.
You can use a little going into the carb, but be sure none of it gets inside to obstruct the flow of fuel. You don't want it on the fuel line compression fittings.
The white teflon tape is for water. The thicker yellow tape is gasoline rated.
Thanks guys for the quick replies
Well, you can use some thread sealer, like Form-a-gasket #2, but NOT teflon tape!! It has its uses, but this is NOT one of them.
Just use tape that is PTFE and labelled as such. I use a little of that blue PTFE Gorilla tape on my fuel threaded fittings.
I personally wouldn't use teflon tape on anything on a car. It's not made to use on gasoline. It's for water. Also it gets stringy when you thread it into fitting. And those pieces strings can get into needle and seat for your float.
I would use a perimitex product that is made for fuel
The Yellow Teflon tape is made for use on petroleum products but the fuel lubes by ez-turn and permatex work much better and are safer.
I'd recommend using this instead where there is fuel. http://www.aircraftspruce.com/catalog/cspages/ezturnlube.php?clickkey=218206 A small amount goes a long way.
EZ Turn lube is the best stuff for fuel fittings. Stay away from Teflon tape.
EZ Turn fuel lubricant.
I have used K&W Copper Coat on fuel fittings for several years without any problems.
When fitting the elbow/cut off valve into the carburetor body, it has to be oriented with the thread to the rear to take the fuel line packing nut. Sometimes this involves screwing it around almost a whole turn and it gets tighter as you go, and you run the risk of cracking the carb body.
Do you fellows have access to a product that will seal the elbow if it is left just a little short of the optimal setting, rather than have to screw it extra tight?
Allan from down under.
The carburetor fitting is a type of "street ell" and many natural gas piping pros will not use them because sometimes you have to go almost 360 degrees to get them tight. The advantage is that you have one less thread to leak. Too tight is just as bad as too loose, as these are a tapered thread, and as Allen stated, can break the female fitting. One trick is to remove the fitting and chase the threads with a 1/4" pipe die, a little at a time, so that it then tightens perfectly. We were trained to use a regular ell and a nipple as each thread only has to tighten 180 degrees but that is not how Ford did it. I have always had good luck with Rectorseal pipe dope, available anywhere. The old gray pipe dope had lead and would seal better, but it was outlawed years ago. There are other modern products that also work, but it is best to get the threads right first. However, you also need to make sure that the fitting is not bottoming on the ridge inside the carb. I looked at a couple of old carbs and the ridge is quit a ways in, but theoretically, if the carb threads are worn, this could happen. In that case, just take a thread or two off the end of the fitting and cross your fingers!
Oh - 1/8" pipe die, not 1/4".