my gk 73a seems to not conform to norm... ive looked for the green wire everywhere. behind sproket cover is a small block with a single black and white wire (only does neutral single contact that rotates with gear selector drum).. cdi has 2 plugs 1= 6 holes but only 4 wires other has 4 holes and 2 wires ..non of these wires show a variable resistance when changing gear ..this leads me to the option that i have a later typr or differant type of cdi ..later microprocessor controled type cut revs at 12500 mine revs to 15000 in all gears except 6th stops at 125000 ..i only have a japanese wiring diagram for all electrics and english for later electronic type which has the same coloured wires bike is a late 88 model so may have mixed 73 and 76 parts im almost at the point of throwing the towel in ... pleassssssse if any one can shed any light i will worship them forever and change my will ( or buy them a pint )if we ever cross paths am willing to travel areasonable distance from winchester if any local-ish people think they can help or will be at odiham trackday 8th june....

Right M8! if its got a green wire on it, it comes from the plastic gear selector beside the front sproket. Ive never seen a Gsxr do 15000rpm so youve poss got a derestricted/aftermarket cdi on it already, are you sure its just not pulling the gear in top, is it a definite restriction you hit? the bike will be going above 112mph if its doing 15000rpm im 5th so it dosent add up. I advise you take the gear selector off and look on the inside, see how it works and eliminate this. Can you post a pic, i will post a pic of the selector with the wires on and i wil test the resistances so you have some actual figures to play with. We can then move on to any other possibles as i also need to get the most out of the Gixer as i want to race later/next year. Jay 'Gsxr400racer' is the man to know as he's raced one for quite a while now. Come on Jay spill the beans.
Chris.

will try to post some pics asap of wires to cdi and this little block on end of gear selector drum .. i have a mechanical kph to mph fitted and clock shows 120mph in fifth gear but just wont pull any more revs once i change to sixth i have gps,ed the clocks and they over read by about 6-8 mph ... bike will happily pull right to the red in 3rd 4th and 5th... bike is running std gearing ie 14t front and 45t rear front tyre is 120/60 17, rear is original 140/60 18 this may affect speedo readings slightly but wont alter rpm.. i have the jap manual for this bike downloaded from here can figure most bits out from pics and a bit of common sence but not this ..you mentioned topping out i can understand loosing maybe 500 rpm but to loose 2000 rpm when it pulls so well in 5th would indicate a limiter of some sort must be electrical as mechanical probs ie valves etc would show in every gear not just top .....enough of my whinging for now ..if you do decide to race im thinking of modding an r6 or similar seat unit and top fairing to fit gk73 just to bring the looks a bit more up to date if interested will keep posted of whats happening with that one unlessyou know some one thats done it already