Arrrggghh!! Rev limiter??

**Motoracer** · 18th December 2003, 22:55

Is there such thing as a rev limiter for a ZXR 400? Right now, the revs on my ZXR is only going up to 10,500. The guys at the workshop reckond it was cause I took out the speedo. I pluged it back in and still it wont go over the 10.5Gs. I think its the carbs mixture settings but I can't say for sure.

I'll still go to Pukie this Saturday and putter around at about an estimeted 150-160. :disapint:

**Kwaka-Kid** · 19th December 2003, 00:42

hmm, strange, i know i cant remove the speedo on my RVF400 because it wont rev over 5,500, but 10,500 sounds bloody high, too high to bother putting one in... All i can think of is just to GET OUT AND RIDE THE THING! thrash the f-ing nutz off the old sucka and bring it back to life, all that sitting must be bad for it... i know my GPz750 with 100,000km on it b4 i first took it to pukekohe, with new plugs, oil, airfilter, etc etc would red to around 7,500-8,000 then splutter and go beserk (in a bad way) and cut out... i took it to pukekohe anyway and man after two laps of screaming down the backstraight it came right and revved happily to its 10,000redline, and another 10% beyond when i got a little keen for more speed.

**riffer** · 19th December 2003, 07:19

Sorry for my ignorance but why would the removal of a speedo affect the speed the bike revs too?

Where's the connection?

**Motoracer** · 19th December 2003, 10:31

Na, I don't think its that buggered. It may be an old bike but it hasn't been used that much. I think the actual Ks on the bike shouldn't be more than about 26K. And I don't know why they would make such a mechanism celtic but they said that when the speedo is not connected the CDI cuts the revs some how at about 10G.

I went to Red Barron today and found an almost definet solution (I say this because I haven't tested it yet). Hopefully with a bit of luck the Derestricter I bought should do the trick tomorrow. Apparently ZXRs have this system when the speedo is not connected the revs don't go higher than 10gs, no matter what gear or speed. Who knows whats the reason/ behind it

P.S. I saw you pulling out of the hospital KK on Tuesday during lunch. I was in that blue 02' R6. I gave a big wave but then realised you wouldn't recognise me lol.

**Kwaka-Kid** · 20th December 2003, 13:16

awesome motoracer.
and the reason they do it is on a bike with a speedo-speed limiter @ 180ish. coz ppl just disconnect to avoid it, so the bike then needs another form of restrictor.
and yes an M-MAX style black box does the trick at a price, so does a piece of wire and a 15c resistor from smiths dick.

only thing motoracer, you said u hooked it back up (speedo) and still did same thing? :S thats a bit odd... the other trick (what i did) was just to leave the speedo on, and on my VFR the limiter is a simple copper plate behind the 180kmph sign and when the back of needle touches it it cuts out bike etc, so i just bent the copper plate back and yay, i can now watch the speedo go passed 180kmph, but i have to try not to watch it too much as i nearly ran off the kink on the backstraight because i was trying to really tuck myself under fairing and just got a little taken in by awtching the speedo and fuck i felt like a bunny rider when all of a sudden i had to make a full on corner out of that minor kink

**Motoracer** · 20th December 2003, 20:48

Well, good news is that the deristricter which was quite expensive did the job. The bad news is that the bike is still slower now than it was originally as a road bike. Much slower actually. When I went to Pukie the 1st time I did 1:17 as my best and now the 2nd time with slicks on with a bit better lines I am doing 1:18. :confused2 (I also changed the gearing for higher top speed the 2nd time)

I was thinking that there would be some sort of an easy way to deristrict it like you said KK but I ran out of time before the track day so I gave in and got the damn deristrictor.

**Kwaka-Kid** · 21st December 2003, 08:36

Originally Posted by Motoracer

Well, good news is that the deristricter which was quite expensive did the job. The bad news is that the bike is still slower now than it was originally as a road bike. Much slower actually. When I went to Pukie the 1st time I did 1:17 as my best and now the 2nd time with slicks on with a bit better lines I am doing 1:18. :confused2 (I also changed the gearing for higher top speed the 2nd time)

I was thinking that there would be some sort of an easy way to deristrict it like you said KK but I ran out of time before the track day so I gave in and got the damn deristrictor.

AWESOME! to hear you have finally made it out there on that bike since all the mods, thats just great to hear and now it only gets easier and i really cant wait till your out there with us in F3.

Sorry to hear you had to fork out the greens to get a black box, but i too have been in situations like that, and it does make things easier. Well those times sound great to me for the first time out on the bike, i think when i first went out on my racebike i would have got around 1:30-not sure, but later that day i got down to 1:23. Just happy to hear you finally took it out tho dude, Good luck for the future with it.