ZXR a few problems after fitting restrictors

[Yoshi]

Hi,

First post, I've got a 1993 ZXR400. I'll introduce later when I'm not stressed about possibly killing my bike!

Having put my zxr back together after putting the restrictors in (please dont say 'dont use the restrictors' as an answer, cos they aren't gonna stay in long)

1. I have got this little piece of squiggly wire which was attached between the throttle cable and a screw underneath it. It is pointed to in the microfiche attached. What is it and how should it go back on, I can't remember how it was

2. Where is the idle adjustment, is it the thing on the end of the bit of wire which is where the throttle rests when it is not twisted. like a knob on the end of a cable which is meant to poke out the side of the bike. When I started it up it idle'd at 4000rpm, as dad and I had been fiddling with this and I think it is the idle adjustment. It seems to be in the manuals but the descriptions and pictures are a bit crap.

3. The second time we started it up, it made a nasty loud knocking noise, I immediately switched it off and now I'm afraid to start it again in case I f*** up the engine.

On the instructions from FI international it says I might need to stick some instant gasket on each side the restrictors to prevent air leakage. I haven't put any, could this be causing the noise?

I'm really annoyed now as I insured it today and was hoping to be out on it, could anyone help me???

[CarneyUK]

Sorry but I can't help as I had my restrictors fitted by a garage.

One thing I will say is are you on a restricted license? and if so do you have the paperwork for the restrictor. It's just I was told they HAD to be fitted by a registered bike mechanic/garage who would fill out the paperwork and stamp it for you then send it off. You are then left with your part of paper for proof. (mine is blue) The fitter has to sign the decleration and also put in their dealer reference.

If that is the case then you may find fitting them yourself will nul and void insurance etc.

I hope I am wrong, and am sorry if I am right. (worth checking out though.)

[Yoshi]

I'm on a restricted licence, I'm putting them in to please my mum (dad doesn't care, he rides a ZX-9R) but they'll be out in a few days.

You don't need all that paperwork, it's a con by the people who make them to stop people fitting them themselves which is cheaper. All the law states is the bike has to produce no more than 33bhp. You can do that however you like, could even pull 2 of the HT leads off if you want, or put a throttle stop on, anything you like. You don't need any signed documentation, they just want more money, greedy gits!

[RedexRobB]

I havent a clue what that thing is, looks like it might just be a clip of some sort to stop the cables moving about? Ive even had a look on mine and i cant find anything aroond the cable that looks anything like that.

Yes the cable with a knob on the end is the idle adjustment screw.

Dunno what the knocking sound is or could be, obviously it didnt make that noise before you tookt he carbs out? So it it gotta be something you have done. It could be that it does need sealer on either side of the gasket, give it a try and see how it goes.

[Yoshi]

Hi,

Thanks for advice, I've now removed the restrictors so it is in the same state as before, and when I try to start it now it again sounds odd as it is turning over, like a knocking noise, it doesn't start but it might if I kept it turning over but I don't want to as its likely whatevers causing the noise might damage the engine

Someone on another forum (BCF) has suggested the noise could be an exhaust nut coming loose, could it be?

[Xphyral]

Well you havent had anything except the carbs opened so far and it was fine before you said. Just fire it up and and let it idle for a min or two, it's highly unlikely your going ruin anything even if the engine is knocking atm. You might discover the noise goes away once the engine is running, you have to remember you've had it sitting with no fuel flow for a bit and all the oil will have drained into the belly and is nice and thick and will take a few mins to get up to temperature and start lubricating properly. Just start it nice and easily with no choke and only a tiny bit of throttle.

Also with regards to mum, convince her that restricted bikes are unsafe due to the fact that it makes overtaking dangerous because the bike isnt producing enough horsepower for it's weight

[masterofinsanity]

Hi,

First post, I've got a 1993 ZXR400. I'll introduce later when I'm not stressed about possibly killing my bike!

Having put my zxr back together after putting the restrictors in (please dont say 'dont use the restrictors' as an answer, cos they aren't gonna stay in long)

1. I have got this little piece of squiggly wire which was attached between the throttle cable and a screw underneath it. It is pointed to in the microfiche attached. What is it and how should it go back on, I can't remember how it was

i had one on mine, can't really remember exactly but wasn't it to keep the 2 throttle cables apart?

2. Where is the idle adjustment, is it the thing on the end of the bit of wire which is where the throttle rests when it is not twisted. like a knob on the end of a cable which is meant to poke out the side of the bike. When I started it up it idle'd at 4000rpm, as dad and I had been fiddling with this and I think it is the idle adjustment. It seems to be in the manuals but the descriptions and pictures are a bit crap.

there should be a cable with a knob sticking out the right hand side above the clutch housing. turn it to adjust idle.if its started idling at 4000rpm after fitting the restrictors you could have an air leak, hence the suggestion of instant gasket

3. The second time we started it up, it made a nasty loud knocking noise, I immediately switched it off and now I'm afraid to start it again in case I f*** up the engine.

have you got oil in the engine? could be anything, who knows when an engine is gonna go bang?When i blew my zxr750 up it started knocking then died, wouldn't start again so stripped the engine completely, never found out what it was, it fired up after the rebuild.
On the instructions from FI international it says I might need to stick some instant gasket on each side the restrictors to prevent air leakage. I haven't put any, could this be causing the noise?

I'm really annoyed now as I insured it today and was hoping to be out on it, could anyone help me???

[Yoshi]

Hi,

I should have said before, when I took off the carbs, (you wont believe me, I didnt believe it!) I found a bolt sitting down on top of one of the intake valves! A bloody bolt, maybe 2 cm long and 1 cm across the head!

And it has been running fine before this, it must have had the bolt in there when it was running. I'm 99.9% sure I didn't drop it in there

I've now taken it out of course

I am surprised it ran, but if that was in there, then what else has dropped down there and possible gone into the cylinder now? I mean someone must have done some toad mechanics on it at some time. I'm pretty sure this bike has had restrictors in it before, as all the bolts on the way down had been undone before etc.

[Rob-ZX4R]

All that is is to seperate the throttle/throttle return cables, it clips in between them once there in position and holds them apart at the carb end.

[Yoshi]

Hi,

Throttle return cable? What's the return cable, it was attached between the throttle cable and the large bolt below it.

Is the bit of wire required, if not I'll leave it out

Have been to see someone in my village who knows alot about bikes and mechanics and he is coming to look at it tomorrow.

I'll let you know how it goes.

[RedexRobB]

Sounds like that bolt might be one of the airbox bolts that you have to insert though a hole in the airbox, are you missing any at all? What happens is they come out of the socket then fall down into the airbox and fall into the air inlet on the carb, perhaps its went right through for some reason or dropped in another way?

[masterofinsanity]

you should have 2 throttle cables 1 to accelerate and the other to decelerate, i've heard of soo many zxr400s with only 1 cable, if this cables frays or sticks with the throttle open you are buggered mate, thats why there's a return cable to shut off the throttle!

[RedexRobB]

Yup thats exactly what they are for. MY XJR400 had a return cable but the hook eye for the end to slot had broken, so some stupid twat thought they would cable tie it, and i bought that from a bike shop!