edge

After years of suffering a flat spot between 4-5,000 revs its been cured by a 2p bit of wire . Following a previous posting I got a reply from Sniffer who I am now forever in debt to He put me in touch with a guy called Shane at B&B Motorcycles Barnsley 01226 391557 who explained that on the large mulit pin socket on the ECU there is a empty pin (top row right hand side) simply fix a wire into this empty socket and run it to earth,he battery will do fine, Then switch the ignition on and off three times this remaps the ECU or activates a dormant map in the ECU either way it works a treat! The power is now smooth all the way from tick over up with no stumbling or holding back RESULT!!!!

I rang Stuart today what a top man, he rembered your motor- however we could not figure out any one thing that might be the problem. But he did ask if I was Australian as he had a e-mail from a guy in aussie with the same problem how spooky is that?

No I thought it was to good to be true! still Iv,e allways got the xjr to fall back on. its better for my legs anyway,and me back, and me wrists......... OH GOD im getting old HA!

tried the dyno route at Wilie and Hollands in Wellington after fitting a dyno jet kit , couldn,t make head or tail of anything. went back to standard settings got a air mixture reading of about 12.5 and nice flat line across the rev range but still had flat spot but not as bad . any way talking to a yzf owner today he said that there is a wiring souloution which bypasses the emissions timing and restores the smoothness ANYBODY HEARD OF THIS MOD OR IS IT JUST WISHFUL THINKING?

I blagged a replacement CDI but it wouldnt start (wrong year aparently) stuck the old one back in runs OK but still holding back at 4000 could it be the Throttle Position gizmo on the carbs changing the timimg as the carbs open? Im going now to beat it with a big stick CLEESE STYLE and reread the Haynes to see if that sheds any light.

Yoda thanks for the ideas In reply when I rebuilt she had all new shims ,valves re-ground Ididnt notice any probs with cams What Ishould have said was while the rebuild was on I ran another motor and the problem was still there so Im still leaning towards carbs or ignition AS to your question yes the hole in the power is at the same place in all gears but most noticable in higher gears as you tend to run through it in acceleration. Waiting on a ECU to try will post later to let you know how it goes

Ive had the carbs apart so many times its driving me mad! If you looked at the emulsion tubes with a magnifying glass you could see they were out of round due to the needles wearing the front edge likewise the needles were also worn on the leading edge, according to everyone I spoke to said this was the problem as the fuel flow was erratic and unmetered as the needles rose in the tubes . So I changed both parts £14 quid each for the emulsion tubes OUCH !!! Plus dyno jet kit. Still no change-runs fine from zero to 4000 ish dies for about 500rpm then pulls away I tried ex-up no change Got fed up with motor hunting while in traffic at around 60mph so changed front sprocket to move the flat spot up the rev range a bit this worked but I just ended up riding like a loon cos it was so much nippier Blew it up ! REBUILT still same flat spot --still puzzled --still need HELP!

thats the next step I need to borrow a CDI and I know a man who has one!

after posting in the wrong place here I am again PROBLEM-- deep hole in power at 4000 bike just dies- BLERUGH! then takes off at about 5000 and runs ok the problem is a ongoing one Ihave replaced the emulsion tubes and am running Dyno Jet needles and K&N air filter Ihave checked the ex-up it seems to be ok ANY IDEAS ? OH SHES DONE 45000MILES NICELY RUN IN WHAT?