Hi there, new to the forum. I bought this bike in early 2021. I've fixed some issues it had with idling and running wise, my issue to this day (without PCV installed) is that it sputters at any constant throttle in any gear at any speed and during first gear take off it also does this. I also should mention this ONLY happens when the bike is warmed up anywhere above 120 degrees and up. BUT, if I full throttle from the constant speed as such as 35mph or 55mph in any gear with it sputtering / jittering, it has no hesitation what so ever and I can run it up to redline without an issue. I have replaced plugs & coils, rectifier, read the map sensor, TPS sensor and all coil wires plus more with ohm reader also tested the FPR (not leaking) to make sure everything is working as should. My bike currently has Coffman's exhaust and aftermarket air filter only installed.
Last year I bought PCV and installed it (figured it was Air/Fuel ratio problem) and after adding the PCV it made my bike not run correctly very low idle / stalling the bike when trying to rev it up. So moving further, I returned the first one after reading on the 600RR forum site where I talked to a guy ("Any Japanese's bike is AOK" was his username) about the same issues and he said the PCV was faulty from factory and worked for him after replacing his, but ever since then I have tried 2 other different PCV with the same issues no matter what map I have installed (I even tried the "zero" map) with same stalling / not idling issue. I have re-tested and replaced multiple parts as stated above to try to figure out what exactly is going on with my bike. Any help will be greatly appreciated, I have not been able to ride this bike as normal since the day I bought it. I am going to try to attach a video of what exactly is happening with PCV installed sorry its so short because of video file size but you can hear what its doing with the PCV installed. If needed I can remove the PCV and also show the "sputtering at constant throttle / first gear take off issue" just let me know.

 

I'd start with a throttle body sync, and perhaps a smoke test to make sure there are no vaccum leaks.
The fact it only does this after warming up, tells me its likely a lean problem. Warming up it runs richer on purpose, which might be masking a vaccum leak.

 

I can assure you there is not a vacuum leak, I have been through this bike checking for leaks more than 10 times, but I will check once more to make sure again. I'm not sure if this matters but the bike does have the clean air mod done to it, I also made sure that it was done correctly and seems like it was by the videos and forums I seen its exactly as shown online for the F4i, I probably should have mentioned this before, I apologize.
About the throttle body sync, I heard that wont help with anything other than idling? I'm not sure if that is 100 percent accurate, but I will try to get the tool to do one anyways, I recently tried my local hardware store to find fittings to do a DIY manometer but I could not find the right fittings anywhere near my location so I will need to buy the actual tool I suppose, but wouldn't this mean it would still have the issues in the video with and without the power commander installed if it was a throttle body sync issue? When I have the power commander unit detached it runs fine other than the constant throttle issue, it idles fine and does not do what it does in the video with the power commander installed. Appreciate your time and input also.

EDIT: I found a sync tool online carbtune sync pro 4 so I will sync them when I receive the tool and post an update, thanks again.

 

Well after using pea based fuel injector cleaner ran through a whole tank of gas, throttle body sync, new airbox , also came with a new map sensor and iac sensor also once again checked all vacuum lines and etc my bike is still is hesitant when just going through the city at 25mph 35mph or even 55mph at a constant throttle, it feels like it’s jerking me back and frontwards when at a constant throttle, also when engine braking it’s not smooth it’s like it’s grabbing and letting go, I’ve tried everything people has posted on these forums and I’m still having issues.