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Hi guys im new to this forum so sorry if its posted in the wrong place.
Basically I own a 91 Zxr400l and have recently done a service on it oil sparks filters brakes
Since then ive noticed that i no longer need to use the choke in the mornings to start it and when I do it doesn't start, however I have to hold the throttle at 2000rpm to stop it from cutting out for around 5 mins from cold. Any ideas what it could be, maybe over fuelling ?
The other problem I had was I went for a ride and 30 mins into the ride the exhaust started blowing and every time i accelerated and as I down shifted. it was continuing to blow violently until the engine cut out, I waited for 5 mins to see whether it had over heated or anything like that but still nothing then i put it on half choke and it worked ! but i had to ride home on the choke which I know is bad but it wouldnt run without it.

Any ideas ?
Thanks for your time
Rob

My first thought is that of it was fine before you "serviced" then it's very likely that your problems are related to something you've done wrong..............or not done

cargo wrote:My first thought is that of it was fine before you "serviced" then it's very likely that your problems are related to something you've done wrong..............or not done

Thats what i was thinking but the trouble is i followed the manual step by step so where could i have gone wrong ?

Well we can safely assue that the brakes arent causing it, nor oil.

So which filters did you do exactly? Air and oil filters? which plugs did you use?

There was a K&N filter put onto it by the previous owner and all i did was buy the cleaning kit and cleaned it up the spark plugs i bought from here http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 698wt_1137 which i guess are the correct ones

thanks again for your help guys

Ive heard about those iridium spark plugs, i think they have a tendency to be a bit unreliable. I also notice that the listing doesnt show a specific plug number. If they are the right ones they should be CR9EIX. Theres also no performance gain from them either, if there is its so small you'd never notice. Did you set the gaps on the plugs?

you cant go wrong with ngk cr9e, no need for this iridium shizzle.

Hey sorry about the late reply
I went for a quick test drive on it today and noticed a loss of power between 4000 rpm and 6000rpm anything above or below that it works fine,
Basically i stripped it all down and the plugs are iridium CR9EIX and the spark plugs have what i believe is carbon (black deposit) on them so i guess it means too rich of a mixture ?
any ideas could it be the spark plugs are dead? or the carbs are overfuelling ?

cheers for your help once again !

well it could be either, did you balance the carbs whilst you were carrying out this service?

I cleaned the Carbs up but didnt balance them as i dont know how to do them

ZXR world really is your friend

http://www.zxrworld.co.uk/zxr400/balancing.html

Hi guys sorry i havent been on in a while
just come back off holiday and im still without a bike !!
ive tried everything i can think of that could be the problem and still nothing, replaced the Coil packs and Ht leads, new spark plugs, new fuel pump , fuel relay and had a look at the junction box which is fine now i crank it over and the exhaust just "pops" and the there's spluttering coming from the air box and it doesn't start
any ideas ??
cheers Rob

Have you got the coil leads on the correct plugs?

1 and 4 and then 2 and 3 ???? they were labelled so i guess there right ?

cylinder numbers go from left to right

left side of engine--->1234<-------right side of engine.

It could be you mixed coil wires up. Theres two wires to each coil, an earth which iirc is black/yellow to each coil and a red on one coil and green on the other.

Leave the earths where they are and swap the coloured wires and give that a go.

The popping and banging sounds like what mine did when i got the coil wires mixed up.

Good luck