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Hi,i have been trying to de-restrict my zxr 400 i have took the restrictors out of the carbs,changed the CDI,But it still feels like it is restricted to 33 bhp and it struggles to get to 85mph!

What else could be restricting it?

did you definatly fit the uk spec cdi?

yea

not sure then mate, i would give it a good service,plugs,oil,air filter, fuel filter, stick some redex through it and get the carbs set up, you sealed the inlet rubbers back up ok didnt you when you put them back?

I'm thinking is it running on all four ?

jimbo , to get past 85 you have to open the throttle mate ha ha , seriously it sounds like you have a carb problem , to lean , to rich, does it pop and fart ? feel flat thru the rev range ? , does it get to 85ish and just not have any power ? or does it feel like its still restricted ? , will it get high in the rev range thru 1st 2nd 3rd etc ? , these guys on here should be able to point you in the right direction ,i have a zxr400h2 and that flys , didnt untill i serviced the carbs and re-set the balance , maybe thats your trouble , what yr is it ?

my one is a l3 model and it will do about 20mph in first 30 in second 50ish in third 65 in 4th 75 in 5th th just slowly gets to 85 ish in 6thbut it feels like it could go loads more because it just stays at about 85ish at about 7000rpm and then the revs dont go up anymore.
it says on my restriction certificate that it is restricted to 92mph and the device is called a blade, that is the washers or is that another restriction device?

im not majorly up on all this but ive done alot of reading on here and other forums and have abit of mechanical know how , ive read that these zxr400s have restrictors in the speedos , rev counters and the cdi units aswell as the intakes , sounds a mine field and im sure it is , if yours is reving out to about 12tho in all the gears but wont reach past 85 you must have sumat going on in the speedo , before you changed the cdi was it doing as it should ? ie, should be good for 120 at least , even a poorly set up one and red line around 13 or 14ish

no it was still struggling to get to 85mph

have you googled blade ? see what it spits out , did you have it restricted ? if not do you still have a contact with the seller ? maybe they would know more , sounds abit like you have sumat in the speedo that see 85 and opens a circut to inhibit it further , changing cdi would make no difference ,if it revs quite happily in first etc then kinda holds back when 85 is reached then it has to be sumat in the speedo , maybe that is what blade means , sumat that the speedo needle touches at 85 , heard that these zxr4s have such a thing in the speedo , you un-plug it and its then the cdi that takes over the restriction , have you unplugged the speedo restriction ? , try the bike with the speedo disconected and see if it is faster and revs past 7grand in 6th , hence you will know your getting past 85 , worth a try

dis conect the speedo cable , not the wiring for now , just the drive cable

ok i will give that a try thanks for your help

jimbo wrote:my one is a l3 model and it will do about 20mph in first 30 in second 50ish in third 65 in 4th 75 in 5th th just slowly gets to 85 ish in 6thbut it feels like it could go loads more because it just stays at about 85ish at about 7000rpm and then the revs dont go up anymore.
it says on my restriction certificate that it is restricted to 92mph and the device is called a blade, that is the washers or is that another restriction device?

i dont think its a restriction thats causing this i thinks something else is majorly wrong, does the bike rev to the redline when stationary (dont hold it there obvisouly).
bike should do way more than 20mph in 1st gear even if it is restricted, the carb restrictions dont stop the bike revving out fully they just make it have less power.

just been reading some of your other posts , deffo sounds like you have a speedo restriction , a cheap way to do it would be to disconnect the speedo cable , not recomended coz speed limits and cameras , ok , next best thing would be to take your speedo apart and look for a pin that when 85 is reached makes contact , bend that pin the hell out the way so it doesnt make contact , as mine isnt restricted in any way shape or form i can honestly say 85 is where it comes into its element , i do alot of motorway and couldnt ride owt that hit an 85mph wall , i hope some of this helps you pal ,if nothing is obvious then hey , just give the bike a good going over and check the carbs , try the no speedo drive cable thing , you never know , still not said if bike revs thru the range in shorter gears ie 1st 2nd etc

OK...................

BEST ADIVCE RIGHT NOW IS TO IGNORE BRIANZXR

Because he clearly doesn't understand the subject.

Jimbo............have you fitted a UK CDI with a blue sticker on it...............?
If so and I believe you have then you should unplug the speedo connecter it's the three wired one with a black connecter.

If you have done this then you HAVE DERESTRICTED your bike.

Therefore you problems lie elsewhere...............something else is wrong.................

As I've already asked it it running on four cylinders ? From your description It sounds like you bike is off one cylinder ?
Or it could be as Extonyg says a carburation problem.

I can absolutely promise you that disconnecting the speedo drive cable will NOT help