Agree@Al1040 if they are pliable at all then you’re gtg.
I believe he is referring to wintergreen oil. Lots of folks report success using this when softening up old rubber bits.

 

you are going to need a set of carb bowl gaskets at least - you can get Chinese ones, they work fine but the probability of all four existing ones surviving is very low. Use one strand from a stainless steel cable to poke the hole in the jet clear - carb cleaner is unlikely to work on its own. The idle jet (small one in the parts diagram) is the troublemaker.

 

Ok mate will definitely give that a go. I was going to buy an ultrasonic cleaner to help and a carb cleaning kit. Will there be any other O-rings to replace? I was thinking i could replace any of them i will come across with taking jets out etc for E10 resistant ones. Dont really want to get into totally stripping the carbs down and replacing diaphragm's etc. Just anything in the bottom end of each carb really while im in there. Cheers for the advice mate

 

You can also pick up the o-rings from here, recommended by one of out senior forum members.
https://litetek.co/Carb_Kit_Honda_CBR1000.html

 

I've purchased a set from here and can confirm that they are quality products. It did take a while for them to arrive but nothing unusual coming from Asia.

 

ebay is the go-to place for chinese rebuild kits - for example https://www.ebay.com/itm/38533149523...3ABFBMrIqX1p5k

the jets are the easiest things to replace - they are brass so no need to be concerned with them. If they look ugly soak them in vinegar overnight.

 

Cheers mate, I have just decided to buy a full rebuild kit from a company that stocks decent quality ones here in the UK now anyway so i will just replace the lot

 

glicerina per ammorbidire i quattro manicotti