Z1OwnersClub GB

Just failed an mot due to throttle not returning quick enough. Made what I thought to be the appropriate adjustments to the cables and when the engines off all works well. When the engines running the throttle is very slow in shutting back down. I,m absolutely at a loss. Anyone got any ideas?

Unless the carbs a very badly out of balance it sounds like it could be an air leak on an inlet rubber and not the cable at all.
That will cause the engine to be slow to settle when running.

throttle slides not set correctly ?

Check the return spring - they are quite big on these old carbs - must have a strong "induction" force on the slides, holding them open a tad

I had this happen.....When I got the bike I replaced the cables....poor return,took em off,compared them to the originals,too bloody short by 30mm,old ones back on nee probs,snapped back straight away!Had a few sherberts to celebrate!

THanks for the advice chaps. Problem sorted. When I started this project three years ago I promised myself that I'd only use nos or refurbed parts where poss. I've just fitted a bed spring as a replacement for the carb return as the original was too weak. Works a treat. Finally got my mot at 1730 which means I'll make it to the Berkshire meet tomorrow. Guy might not thank you though.

[ I've just fitted a bed spring as a replacement for the carb return as the original was too weak. Works a treat.

Ha. love it....

Hope the bed spring was from her side of the bed