Well last night I cracked a 2ed gas inlet on a carb. The new brass "L" bought from a supplier was too loose so I turned it one more time. This is one with threads at both ends so I could put a shut off valve by the carb. I don't have a way to test the brass but I am thinking that the new brass is harder then the original "L" fitting and is putting more pressure on the cast inlet. Right now with thread sealer I have it down to a minor seep but I will have to pull the carb of to make repairs. Has anyone else run into this?
When you say "thread sealer" do you mean Teflon tape? If so, it's notoriously bad at sealing loose fittings.
Try Permatex, and make sure you get the one that's fuel-proof. It comes in hard-setting and non-hardening. I'd suggest the non-hardening.
I am using the fuel proof non-hardening Permatex white thread sealer.
Mark,
Did you chase the treads in the carb with a tap?
I've done that on all the carbs I've done and no problems....so far. Amazing the rusty dirt curd that comes out of those couple treads.
Larry
Good point about chasing the threads, I am real sure I did when I cleaned the carb over a year ago. The casting is thin in this area and the carb is over 80 years old. So we are on the same page, it's a Kingston cast iron large bowl nut L4.
New brass mostly has no or very little lead in it and is so hard and brittle it will snap before it will seal. Thank the EPA.
The new no lead brass is also poor because it is very hard to anneal. It is much less conductive without the lead, so the outside of a brass billet will be over annealed before the inside even gets a chance to heat. Yes, thank the EPA for many things...
Thank the EPA for the downfall of civilization