Carter yfa on a `78 f100. I was sitting on the living room floor replacing various parts and while I was installing the main jet, my dog decides to jump up on my arm. Long story short, this caused me to cross-thread the jet. (The threads inside of the carburetor, not on the jet) I believe that the metering rod leans in a way that would compensate, but I'm not sure whether or not its safe (for myself or my engine) to run this Carb again. Any help, advice, stories, or warnings would be very great and definitely appreciated.

-patientzero

 

I wouldn't let the jet sit in the carb crooked. While it may not be a safety issue, it isn't the way to go about rebuilding your carb. The YFA can be a little touchy. Try taking the jet back out and finding the right size tap and maybe you can re-thread the hole the jet screws into. If you do this, make sure you don't let any little pieces of metal residue from the tapping in the carb.

Another thing to check and re-check is the float settings. Also be careful putting the top (that holds the float) into the carb body. It's easy to bump the float and mess up the settings. Been there and done that. The YFA is pretty basic but I find the settings are critical to good operation. Just take your time and make sure your setting are correct and you'll have a good operating carb.

 

Thanks! I hadn't even thought about trying to repair the threads! I'll have to give it a shot between shifts tomorrow! And I have noticed that its very hard to maintain float adjustment. I'm guessing its just as you mention and not taking quite enough care during assembly. Improper float height would be a likely cause of rich idle but fairly clean combustion under acceleration, wouldn't it?

 

Agreed. A tap with the proper threads should clean that right up and get the jet sitting straight. A crooked jet may or may not leak, but I imagine it would ride on the side of the metering rod and wear it right out.

And yeah, those floats are a pain. Mine would get bumped out of alignment whenever I'd hit big bumps while off-roading and camping. It made for some miserable drives out when it would get so knocked out of place that my engine would buck and sputter the whole drive back. Fun stuff.

 

Just wanted to thank you guys for the suggestions... I pulled the jet out today, took a trip to the hardware store, and found the closest matching tap that I could find. Turned it by hand, blew it out with the air compressor, and the jet turned back in like a charm! Just waiting to pick up a new float @ o'reillys in the am!