to the forum Barry. Sound's like your going to be very busy over winter. There are a lot of knowledgeable FZR owner's here , they'll be along shortly after there morning Coffee fix.
Those inlet rubbers sound like potential culprits as they would account for at least some of the symptoms If you are going to pull the engine down, rings are available on Aliexpress, reconditioning the cylinder head can be difficult as a result of the sizes involved. A 2KR will have 4mm valve stems, machining parts for which are available to cut seats, the valve sizes themselves are the problem Let us know your overall intentions and plans and we'll hopefully help you avoid the pitfalls
Welcome to the forum, post up some pic's if you can Have you pulled the spark plug's out to check the condition ? If you find a rusty looking plug then i suspect your suspicion's are correct 2KR Intake manifold's can be costly, i think genuine is your only option unless Kiwami have started making them? https://www.ebay.com.au/itm/YAMAHA-...446933&hash=item2ceddf0a7d:g:aaQAAOSwRM1dTQKI AHL engine part's are recommended over other's Gasket set https://www.aliexpress.com/item/323...earchweb0_0,searchweb201602_,searchweb201603_ https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20201021155147&SearchText=fzr250+fz250
Have you thought about trying to clean up that journal. Give it a linish then put a micrometer over it. You might be surprised. I have worked on a lot worse than that.
