Carb problem

[Rollup46]

I have a 1989 FZR 1000. It starts ok on choke but try to rev it or release the choke and it cuts out. I took the airbox off to get access to the carbs. When opening the throttle the butterfly valves open ok. The throttle or the choke doesn't seem to operate the slides.
Does the engine need to be running to create a vacuum to operate the slides?
By the way the bike has been stood for 18 months and has only done 18,000 miles from new.

[DonTZ125]

The slides are vacuum operated. I would suggest that in the 18 months of sitting there, the fuel has turned to junk and fouled your passages and small jets. Pull the carbs, strip and clean and synch.

[Stig]

bet it ticks over OK but cant build up the revs.......

Mines the same after being stood. Try blipping the throttle a small amount at a time to slowly bring up the revs. As they rise it'll start farting, banging and popping. Its stale fuel and gum in the carb thats being cleared out as its pushed through. One way to prevent it happening again is to either drain the floats before standing up or add fuel stabilizer

[KaspenOne]

I would just pull the carbs. it wont take long and is a easy job to do. also inspect the tank, if it has rust flakes it will go through the gas and reach the carbs if the fuel filter has gone bad. take apart and clean the float bowls and jets. adjust float hieght if needed, then sync using a vacum gauge and put back together, better to clean it out then avoid another problem down the road becuase it got clogged again.

[Rollup46]

Thanks for your help guys, I sort of thought it was down to stale fuel, but thought it might have been an air leak between carbs and motor. Off in the garage now to sort it!

[maelstrom]

This might be helpful as well.
http://www.litetek.co/Guide_MikuniBDST_ ... gAssy.html

[Stig]

Thanks for your help guys, I sort of thought it was down to stale fuel, but thought it might have been an air leak between carbs and motor. Off in the garage now to sort it!

Did you get it sorted and what was it???