carb with missing orifice in hangy down thing

well, what do i do here?

one of the carbs has a big hole where i'm guessing should be a much smaller hole.

also, what is the name of the "hangy down thing". fuel pickup?

 

If it's what I think it is, you are one in a million to have that out of the carb bowl. The hole that the tube goes down in has a SMALL orifice pressed into the bowl. THAT is what is very difficult to clean. NOBODY I know has been able to remove that orifice. It looks like YOU did! As long as the hole is clear of debris, you should be able to just leave it.

 

Yes the enrichment circuit jet.

 

That's it!!!

 

No it's not! The jet that is down inside the bowl is just a very mini version of the main or pilot fuel jets. On 1980 XJ650 carb bowls (maybe early 1981's, too) the starter jet actually is removable, as it is screwed in rather than pressed in.

All of the suction tubes should look like the one "with orifice"; the suction tube missing the orifice is somehow damaged (the restrictive plug has fallen out or been drilled out, etc. or somehow removed).

 

So you think it will work fine the way it is?

 

Not sure about that, there's a reason Hitachi built the carbs with that restriction in it, you're going to be sucking up a LOT more fuel thru that tube than thru the others..............

 

I personally would get another carb body , the one missing the restriction means your enrichment circuit on that carb will not work correctly.

 

This is correct, it will empty the sump it’s in very quickly, and then just suck air and the amount of fuel let through by the orifice in the bottom of the float bowl. Most likely you will lose enrichment on that carb.
You have another three though, so it should start ok, but I guess the warmup might be “lumpy”. Once warm the problem goes away.
That jet is just pressed in isn’t it? You could file the end of the tube, then tap it back in?
Last resort, as @Jetfixer suggests is replacement body, but I wouldn’t be rushing.

 

see if you can find some round brass stock . sold at hobby shops K&S is manufacture some hardeare stores carry it too
and drill a #80 (i think thats the size) hole in it and replace the plug
you may have to solder it in place.

if you need to reduce the diameter of the rod you can put it in a drill and spin it and polish it down with fine wet/dry paper

your other options are a new carb body or find someone with a junk broken body and see if you can swap the tube

Order Brass Tubes, Rods, Strips & Sheets Online | K&S Precision Metals – Tagged "Rod" (ksmetals.com)

 

I don’t think so….. the enrichment jet is in the bowl well. I’d get a different body

 

Back to the drawing board. I need to study carburetors more .

 

Did it start and warm up prior to this going missing? If so what’s the issue?
When cold it fuels one pot.
Once warm it doesn’t do anything.

 

why not solder the end of the pipe up, then drill the required hole through the solder
i know its a tiny hole , but maybe if you take the other carb body to a tool suppliers, they may have a drill to fit the hole, or very near

 

i have a new-er one coming. someone has a bunch of xj700 stuff on ebay.

 

Make sure you get the correct one..... all 4 are different from each other on the 700.

 

How do you know which bike he is working on? He's got quite a collection........

 

Cuz he said this.....