What is this Carb part? VFR700

Can anyone tell me what this brass part is?

As you can see, when I bought the bike one was missing and the aluminum damaged. How it happened? I have no idea.

Anyway, I found a matching part (same tiny hole size) on a similar carb and installed it really well so it won't come loose.

I've got an idle problem with this cylinder #1 not firing. I know the spark is nice and strong at idle, but it's not firing 100 percent. The exhuast pipe from the head is only warm compared to the others being hot after 30 seconds running (no choke).

Could that brass part be related to my problem or just a coincidence?

Thanks.

 

that lil brass piece is the emulsion port for the idle circuit dont quote me on it im just shootin from the hip if im right. the idle circuit will run really really lean. you might be able to fatten it up by screwing the idle mixture screw out a lil bit but i think that has to be there it restricts the volume of air being drawn through the emulsion tube of the idle circuit. but then again it may be for the main imulsifier like i say im not sure but from the hip it shoots

 

I fixed it up and it runs great, just kinda uneven at idle.

Maybe I should apply some JB Weld all around the edges to make sure it's not leaking?

Judging by the size of the hole, even a tiny amount of air leaking past might throw things off.

 

O Dammit I just cringed a lil at the thought of it coming out while hammerd down.. make sure that thing is very secure. Know jb weld would prolly work just make sure all surfaces are clean. Idk I think I would find a way to pin it or maybe a small screw with green locktite. I hope it all works out great man. Ne thing like that always scares the shit outta me though

 

I was thinking of adding a short length of braided steel line. Crimp a loop in one end and clamp it under that bolt near by and put the other end into the JB Weld. That way if the brass piece comes loose it will hang by the cable and not fall in.

Back to the original problem, do you think that Brass piece would be messing up my idle?

I thought I cleaned the carbs really well, but that carb might have a blocked pilot valve circuit causing it to run lean at idle, but be fine once you bring up the revs. That's my guess. :unsure:

 

if the bike has sat for any length of time the idle circut probably has crap in it.. it needs a good cleaning(pulling out the jets running a wire through the ports blah blah blah .. use very little JB weld or just source another set of carbs ...

 

It is common for the tube to get broken off when trying to remove the manifold with the carbs still mounted on the engine. You will need to replace that carb to make it right.

 

I don't see how that is possible.

Are you thinking this brass piece is leaking air around the edges and this is why this cylinder misses at idle?

 

I played around with the pilot screw. I turned it all the way in, then out to 4 turns with no change in the engine. It's got to be blocked, wouldn't you agree?

 

I would just go with what TOE suggests.... you are going to put money into a broken piece when you could just go to a salvage yard (or Ebay) and pick up another set of carbs ....

 

I'm putting zero money into this. I've already ridden over a 1,000 miles as is so it's not that big a deal.

I might pull the pilot screw all the way out and squirt some carb cleaner in the hole and follow with some compressed air. Just removing the right side fairing for access. No biggie.

Can anyone confirm that the brass part is the emulsion port for the idle circuit?

 

"Air corrector jet" i believe it's called, and Orion has it right that it ducts air into the main and pilot jet emulsion tube areas. Has no real effect at idle speed, but you need to check with carb spray or thin wire that the passage below the brass bit is clear.

You need to try a carb synch before concluding just what your running problem is.

 

Yes, they might be related or it might just be a coincidence.