This person asked about the hoses function. No one seemed to answer that. I too have the same question, the #1 and #4 vacuum hose that lead to the air box connect to the tabs underneath. The tabs have a very small hole on the front side that the hose connects to, but nothing on the other side (meaning it's not a through hole). What exactly is the purpose and function of that. And if all that's needed is a closed end would pinching the hose shut do the same thing as connecting it to the air box? If anyone has an answer please stay focused on the question about how it functions and not worry about what I said about pinching it shut, I was using that as an example. Thank you!

I posted this in another thread, I need this answer really bad to understand. Please someone explain it to me

Okay, I ordered a replacement housing for the air box. Fixed it. All the hoses are connected, I'm not convinced that was even affect anything. I replaced the speed sensor, all though the speed is reading incorrect. But that's due to the gear ratio change when I updated the sprockets.
Bike is fully assembled and went for a ride today. The ride wasn't bad but deffinetly the underlying cause is still present. There is little torque or excess power when beginning to speed up. Like any car easily could overtake me without even trying (even if I full throttled it). There are no codes, no noisess that I can hear. Any ideas? It didn't act like It was gonna break down like it was doing before.

Another clue, when stopped at a light, when I would go to engage I give a little throttle and release the clutch (like normal) but it putters and even after "catching" it has no power/torque for a few seconds before it starts getting a little faster. It also high revs without any feel of a power band.
Please help, I'm out of ideas and I need a solution. I hope to get someone to look at it soon but until then... y'all are my only hope.

You running a power commander?

California model with an O2 sensor?

I believe it's a California model with o2 sensor. No PC.

And you've no codes?

No codes.

74demon, it's been a long while since we last spoke on the matter but until recently the problem seemed to go away. Well I began thinking that maybe the bike was just running out of gas. Reason I thought this, it seemed to only happen right before the reserve came on. Made me think the reserve sensor is wrong and I'm running out of gas sooner than later. But the other day (with a full tank) it started happening.
I turned the bike on just now and removed the FPR vacuum hose to check for leak. No leak.
Then I reached further and clamped the hose and the bike jumped up rpms. Here's where I need the help. Does that tell me that's the problem? Here is what happened.

Before hose clamp:
Bike was hard to cold start, had to hold throttle open a little to keep it from stalling. Then once it started it held 900-1000 rpm idle. Which is low. Attempted to blip throttle to get some rev noise and the bike rpm would either drop a little before increasing or wouldn't respond until I held a twisted throttle position. Basically poor throttle response.

After clamping the hose:
The rpms jumped to 2000, and was strong and steady. Then when I went to twist the throttle, it was super responsive and even the slightest blip made the rpms jump (relative to how much I twisted)

Is this enough information to tell me if the FPR is malfunctioning? I heard another sign is fouled spark plugs.

Anyone with answers/advice would be really helpful and is greatly welcomed.

In addition: about three months ago the bike went from terrible cold start, like I described above, to starting up within a few seconds. Now (couple weeks ago) it has gone back to starting like I mentioned above. Seems to correlate, timeline wise, with the riding problem I've been having.

I think it's the FPR.

To test that, you pull the pipe off, one side will usually have fuel in it. You weren't 100% clear when you said you checked for leaks.

Anyway, it's a vacuum hose, shouldn't have any air leaks in it, or any fuel in it.

Sorry, there was no fuel or air pressure coming from the vacuum hose pipe on the FPR. The hose had no fuel in it either.

on both connections?