I start the bike up and it purrs like and kitten for 3 minutes then it just goes erratic, unable to hold steady revs, seems slightly starved then races ??

I'm in the UK but this CBR spec is for the US and i've never seen so many pipes come from the carbs to crappy emissions thingy me bobs before? .

I've done a carb strip and clean, new plugs, freshly charged battery, checked all terminals, new filter ???? I'm baffled.

advice required thanks

 

Sounds like a air leak.
Possible stuck throttle body, stuck choke.

 

Can all the tubes for emissions be blanked off to make it European spec or are the other components fixed to the bike like the canister ect?

 

It sounds like it is going lean before it quits. You did not say if you are able to keep it running by revving or if it quits while underway. If the tank vent is blocked, some fuel will slowly make it's way to the float bowl, but not enough to keep it running. Will it idle with the tank cap open?

All the emission hoses can give you vacuum leak problems, which again makes for a lean out condition. On my US/California spec '94, the system was all still in place. I did read where other owners had removed the PAIR/PARE? system and plugged the ports on the front of the head. Maybe see the search section of the forum. I don't own the bike or manual any longer so research is limited to my feeble memory.

So check the tank vent and inspect hose connections thoroughly for starters.

 

all good one hidden hose had popped off.

 

Good fix congrats