Anybody have any ideas what's going on with my bike?

It was running nicely, took me 1200 miles round Scotland without a single problem. A few days after I got back, one of the carbs started leaking petrol from the float bowl overflow, so I figured it was time to do the dreaded O-Rings.
Anyway, having eventually got into the float bowls, I replaced the float perch and main jet o-rings with Viton rings. Certainly looked like the float perch was responsible, the original was very loose.
I didnt replace the idle screws as i'd bought the wrong size, and they looked ok, not hardened at all (yes I know.... ). I wanted to get out on it this weekend, may be the last bit of good weather

Unfortunately, having given it a test ride today, it doesn't seem to running correctly. It's reluctant to rev, particularly around 5k. It runs ok, doesn't stall but it just won't rev out. Does anybody have any ideas what the problem could be, and how I can fix it tomorrow morning!?!

EDIT:
I have another question actually. My carbs have two large hoses leading to a filter on top of the airbox. I'm guessing this is to provide atmospheric pressure for the diaphragms. However, there's also a pair of hoses near where they attach that appear to go nowhere. Anybody know what that's all about?

I just replaced mine and had the same problem. Mine was due to the way the fuel and petrol pipes were placed. Even the slightest kink caused major problems. What I did in the end was to swap the main fuel pipe for the reserve one just so it didn't kink, not ideal, but the bike is running amazingly now.

Thanks for the reply, but it turns out I was missing a piece of the carb, that's probably why it didn't run
Having said that, I did find that the hoses needed careful routing to stop them being squished when the tank is put on, so certainly something to keep an eye on.