What are they symptoms of throttle bodies out of sync
 

I've tried searching the above question but can't seem to find an answer.

Any help would be great.

throttle body sync is fine tuning of airflow when the throttle plates are closed. main symptom of bad sync is a poor idle. it only smooths out idle and initial off idle acceleration.

the f4i is extremely easy to sync compared to other sport bikes

I wonder if mine need doing then, idle is fine but when I pull away in anything below 3000rpm it bogs down like crazy

i doubt that's a throttle body sync issue...

What problem do you think it could be?

A poorly running engine, which can be caused by many many things.