www.zxrworld.co.uk

How can i tell if my bike is a uk spec or import and is there any difference in parts. My uk spec Honda NC30 had different exhaust system to the imported ones and thats what i need for the ZXR. Are they the same of different? Also if my bike does turn out to be a UK spec one was it still restricted or do i need to derestrict it? if so how. Its being used for track days only.

uk bikes have an mph speedo, different cdi, and carb heaters and sometimes different needles/jetting

import bikes require the speedo to be connected or they wont rev over 10,000 rpm, once connected they wont exceed 180kph

to get round this either,

1) modify the speedo (there's an article on here somewhere about it)
2) fit an Mmax box
3) fit a uk cdi (this doent know about speed restrictors or whether the speedo is present and has a slightly higher rev limiter)

also, early bikes (pre L3 ?) have better cam profiles for track use

Well its got MPH speedo but it is a bitsa bike so im not 100% sure. Would the frame/engine numbers tell me anything?

unclesparks wrote:Well its got MPH speedo but it is a bitsa bike so im not 100% sure. Would the frame/engine numbers tell me anything?

they might, but i' cant decipher them .. apart from the differences ive stated, they are the same bikes .. so does it really matter ?

Also, as i recently found out, 31mm carbs.
Ive a beater l4 import, which i stripped, and noticed the carbs ar'nt bored to 32mm as my import H's, they are smaller...which kinda sucks.
i wonder if all L imports have these?

weird, ive only seen the smaller carbs on the early '88 ZX4, all my H's and my L4 import had 32mm ( i think, infact, im sure they did, ive still got the L4 carbs cos I fitted them to Emma's ZX4 to replace her smaller original ones)

do they have carb heaters ?
are the needles "stepped" ?

no heaters, havent had them apart yet to check needles, they look the same as my other L carbs, but the bore is smaller. The bellmouths smaller, and the carb rubbers you could'nt squish a pea thru!
Ive also got a set of H1 sp carbs, these are different again. i thought they where the same as H/L 32mm jobbies, but on inspection the have different float bowls and needles..
Also zimm, i have made my standard H airbox into a ramair box, and it works quite well. save yrself a bit of money if you track your new H. I just moulded a scoop into the front, cut my rad usual style, plated over the existing hole on the top of airbox. Vented the 2 breather pipes into the airbox. Ripped the foam off the air filter and all the plastic strips and shiet in the box, and just left the metal gauze in there.

yeh, they sound like ZX4 carbs .. identical in every-way just smaller internally.. i asked about the needles because the ZX-4 runs needles which have a MASSIVE step in them ~8mm from the tip which richens up the mixture at the topend.. probably to do with the weird resonance from the ZX4 airbox

airbox sounds cool,, you reckon the "ram" effect is real ? or if you just get more power because its less restrictive ?

(it might be worth you finding the front half of a ZX4 airbox to base a 2nd gen version on... bolts right up to the other half of the H but is bigger.. you may need an L tank to make it fit though)

looking at making something similar to the kit box but out of ally for the hybrid.. need my frame back first though.

the H will be tracked, ive put too much work into the other one to lob it into a gravel trap. For now its a case of just get it running, so that i can take my car off the road for a week and fix it*, then finish the hybrid.

*ive had bald tyres for over a month (1000miles !), my exhaust is falling off, brakes shot, wheelbearings shot, engine burning almost as much oil as petrol.. and all because i need something i can drive everyday (and i have plans which will take more than an evening in the garage)