2001 Yamaha waverunner GP800R - Mikuni carb question

[Cptkid570]

2001 Yamaha Waverunner GP800R. 2 cylinder, so twin Mikuni carbs. In the middle of the carbs (outlined with the red box) is something that when I pump the gas lever, it squirts gas into the top of the carb's body (yellow arrows -- the fuel lines are currently disconnected). I have 2 questions.
1. What is this called? Is it some sort of a primer?
2. where the fuel lines connect to the carb, one of the jets appears to be clogged as fuel isn't getting in, but it is not clogged. It has some of a tiny sea****-type ball valve in it. Is it supposed to have that? What if I hollowed it out or put a different fitting on it so that gas could always flow through that? Again, how is this supposed to work?

The 2nd photo has the fuel line connected to this inlet and shows where it goes into the carb..

Again, wondering what the purpose of this is.. is it just a primer?

It is not the oil injection, that is a separate inlet.

Thank you for any responses.

 

[Cptkid570]

The fitting that goes into the carb seems to have a sort of anti-siphon valve/ball in it.. just don't know how necessary that is

 

[QBhoy]

First pic is oil injection line, is it not ?
i used to have this very ski. Almost certain it is. I blanked these off and pre mixed. Took oil pump off and blanked it.

 

[QBhoy]

Mmm. I’ll need to think about it again. If you think it isn’t oil line. Show me a pic of that and I’ll likely remember. I have the drawings for it somewhere.

 

[QBhoy]

First pic is defo the oil line.

 

[Mikey N.C.]

That is accelerator pump and line ( the small gray hose) those are very lean bn carbs. When I throttle wide open it spits a little fuel so engine doesn't stall.

 

[dazk14]

That is accelerator pump and line ( the small gray hose) those are very lean bn carbs. When I throttle wide open it spits a little fuel so engine doesn't stall.

+1 In addition to that, those carbs need to kept clear/clean internally. clogged jets are the most common cause of piston/ nicasil cylinder damage. If rebuilding I suggest Mikuni kits.