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View Full Version : So um... yes I will be a bi*ch and not rev pas 8K



niero
23rd August 2008, 23:40
Hi all. Got a problem with my ZXR750 h1 (89) I could use a hand with. The old girl wont get over 8000rpm in any gear at any speed. Feels like it is rev limited. I've changed everything from the plugs back to the coils. Its like Kawasaki is taking after those annoying programs on the internet which require you to upgrade in order to use them fully, and so our "trial" key has expired in 08, and in order to go past 8000RPM we need to upgrade to the "full edition" or something. Anyone got a clue? I mean honestly there got to be up something with this

James Deuce
24th August 2008, 00:40
I have a friend who had the same symptoms on a new one many years ago (19 - Gahh!) and it was the CDI. Exactly the same symptoms.

racefactory
24th August 2008, 18:14
so what happened in the end with your friends one? did the cdi just 'become fucked'? I don't know if they can do that?

so could you never get over 8 rpm ever since you had the bike? does it bounce off like a limiter or something?

good luck.

interesting

James Deuce
24th August 2008, 18:18
CDI was fried by a jump start. No signal over 8 grand. Really odd, but not unknown apparently.

Drew
24th August 2008, 18:20
I have a friend who had the same symptoms on a new one many years ago (19 - Gahh!) and it was the CDI. Exactly the same symptoms.

I concur with Jim.

The cdi is mapped to change timing at certain rev markers, if 8000rpm is one of said change points, and the new circuit (that's not what it is, but you get the idea), is bung somehow, it'll just cut out cos it dunno what to do.

racefactory
24th August 2008, 18:25
interesting- sounds like this is the problem then.

doesnt seem to be any on trademe at the moment.

James Deuce
24th August 2008, 18:28
Try ebay in the US and UK, and also France.

FJRider
24th August 2008, 18:31
When you go to price them at a shop...take a chair, and be sitting when they tell you how much...

Drew
25th August 2008, 17:15
They are fixable, it is only a circuit board. Burnt out resistors are easy to spot, and capacitors can be tested. I tackled one myself a couple years back, but now I have an electronics engineer for a flat mate:2thumbsup


Crack that bad boy open, or send it to someone you trust to do it for you.

FJRider
25th August 2008, 18:31
They are fixable, it is only a circuit board. Burnt out resistors are easy to spot, and capacitors can be tested. I tackled one myself a couple years back, but now I have an electronics engineer for a flat mate:2thumbsup


Is she a good cook too ???

Drew
25th August 2008, 18:53
Is she a good cook too ???

It's a him, and the sick bastard lives on rice and tuna most the time.

FROSTY
27th August 2008, 12:04
Not disagreeing at all with other posters--most likely is the CDI
BUT there are also a bunch of sensors around the engine. One of them might also be crook. I did a Kiwi engine into a jap import ZXR once and it was a ferkin mare. less sensors on the japper or summat

sugilite
28th August 2008, 17:17
Heyya, my one had this exact same problem. Someone had de-restricted it (was jap import model) and the diode they had used to do this was burnt out. The problem was sorted when I replaced the diode. It was running off a wire coming from the CDI itself.

niero
1st September 2008, 19:18
Sweet, thanks a lot guys, I have er booked for a check tommorow. Also here is my understanding of CDI, its a timing device for the sparkplugs... then what are the magnetoes for? I must be thinking the wrong thing here. So, a crash course on CDI's would be awesome. Also whats with the sensors? The RPM Gauge seems to be fine had a look in the engine, looks very good for something that has done 100K. Yeah she feels like she is rev limited at 8K, almost gives up but when I go downhill with my throttle wide open she goes further, but good god it sounds like only one of the pistons is firing at the right rate at a time, you can hear her skipping so bad it hurts m heart. Also SOMETIMES in neutral after a ride she can go behoind 8K, (wtf:() yeah I bought er like that. O well... Thanks a lot for the feedback guys, much appreciated!

flyingbrick
1st September 2008, 20:19
Is there not a switch or something in the box which limits RPM to 8k in top gear? (hence the de-restricting comment).

I'd get that checked. check for a loose plug or damaged wire.