4l0 : are these the right floating bowls?

[xian911]

(very) hard cold start. Right cylinder backfires. Rev ceils at 8.000rpm. When hot & running, no change when choke pulled.
carbs stamped 4L0-01. Bowls stamped P1-1 and P1-2
Already done : new jets, new valve body & o-ring, float level 21mm, ultrasonic cleaning but without removing brass balls. 
Have already read a lot. I'm wondering if the bowls are the right ones because I don't see a hole/jet on both bowls( see red circles in picture) If right ones, which is the left one?
Anyway choke is not working and that is the explanation for bad cold start.
But what about the rev ceiling and backfiring? Engine was rebuild (crankshaft, pistons) with all gaskets & oil seals renewed. Symptoms were the same before rebuilding

Needles jets :  345-P2 needles :  5K1 position 3
Main jet 220 idle jet 22.5

kits bought from same supplier for years. He supplies many classic racers.

4L0 bowls by xian911, on Flickr

1703340740676 by xian911, on Flickr

1703340740682 by xian911, on Flickr

[tony2stroke]

Need better picture of the red circle bit taken looking from opposite side you have done, I can't see a tinny hole drilling in the center, 1 bowl should have said hole,  also right bowl in your picture looks to have a very small hole in the brass pipe, better clear images of these areas would help.

The bowl with the small hole drilling in the red circle area is for the left carb (viewed sitting on bikes)

[shaunthe2nd]

The LH choke carb should have the bowl with the extra hole.
I'd be taking the brass balls out and cleaning the air circuit if I was you.
And are you using genuine parts? some poor quality rebuild kits about.

[xian911]

Dec 23, 2023 11:46:54 GMT 1 tony2stroke said:

Need better picture of the red circle bit taken looking from opposite side you have done, I can't see a tinny hole drilling in the center, 1 bowl should have said hole,  also right bowl in your picture looks to have a very small hole in the brass pipe, better clear images of these areas would help.

The bowl with the small hole drilling in the red circle area is for the left carb (viewed sitting on bikes)

There is no holes. Nor on left red circle nor on right one. Pictures taken before remounting carbs on engine...
I will tear them off and take better pictures

[shaunthe2nd]

If no holes, you have 2 RH bowls, hence why choke not working.

[tony2stroke]

As above 

[xian911]

Dec 23, 2023 13:28:22 GMT 1 shaunthe2nd said:

If no holes, you have 2 RH bowls, hence why choke not working.

Thanks, you confirm what I thought. However it's strange that bowls are identical but marked differently P1-1 & P1-2

[reedpete]

Probably Just cavity markings from the casting tooling to identify what came from where

[huxley]

I would definitely remove the brass balls and clean out the circuit, I did it on my 250 and it starts much better now.

[xian911]

Dec 24, 2023 8:00:10 GMT 1 huxley said:

I would definitely remove the brass balls and clean out the circuit, I did it on my 250 and it starts much better now.

 As far as I understand from posts I have to remove the big one(lowest) on the rear(air filter side). Only this one?

[shaunthe2nd]

Yes just one per carb. 4.5mm dia. Plenty info on here if you search. Quite straight forward to do with often a large return.

[xian911]

Dec 24, 2023 11:22:54 GMT 1 shaunthe2nd said:

Yes just one per carb. 4.5mm dia. Plenty info on here if you search. Quite straight forward to do with often a large return.

Thanks. Search engine works again  .   
Merry Xmas