www.zxrworld.co.uk

I was on my way back from work last week and was giving it a bit up the sliproad, i was just on the brink of changing gear so was on the redline or as near as damn it and it just went bang.
It was just a backfire not an engine failure but the bike cut out straight away and as i coasted to a stop if i let the clutch out it was just a stream of backfires, if i dipped the clutch it died altogether. the bike still fires up but just as its about to pick up revs it backfires and dies again.
I am convinced this is an ignition problem as i am guessin the bangs are off fuel that isnt getting burnt at the right time.
So far i have changed the cdi unit and both coils but the problems still there.

could this be the pickup coil perhaps ?

Has anybody any ideas or has encountered this before as it is driving me nuts and i need the bike for work

Any help will be greatly appreciated, thanks for taking the time to read this

Ben

does sound like an ignition problem.....................have you looked at the ignition rotor is it still there? damaged ?...........maybe broken cam chain tensioner blade ?

Does sound like ignition timing is out which could be down to cam chain jumping at high revs (worn components)

Check your valve timing is still aligned right , hard for pulsar to move as it should have a crank pin but you never know !

Top Tip:

If your going to thrash your bike (thats everybody BTW) make sure you know the bikes service history. They are designed to run to the redline but only when kept in peak condition.


MM!

Thanks for the help.

My cam chain and tensioner were replaced about 2k ago just before i bought the bike (or say he says) and have the reciepts for the parts, i changed the oil and plugs and filters and had it rolling road tuned with a dynojet kit and k and n about 1k ago, so i think the bike is in pretty good shape engine wise, that is trusting that the guy actually changed the cam chain and tensioner.

So this is turning into a nightmare !

Sorry for sounding dumb but.....what would the ignition rotor be and where would it be located ?
Also is it an engine out job to check the cam chain tensioner is still there ?

Has anybody had a cam chain go ? would this happen ? or would the bike not turn and fire in the first place ?

Again any help would be greatly appreciated.

With bike on side stand you can remove pulsar cover on front left side - there is a small inspection window for checking the ignition timing with a strobe.

Look up thread on valve / shim check for how to set it up on the timing marks , with the cover off it will be easy to see if all is well or not.

You need rocker cover off to to check that the marks on the cam wheels are correct too. This can all be done with engine in frame but you will need an inspection mirror to se the cam wheel marks.

If chain had snapped , valves generally get bent on the over run and the bike would never start again.

Still think the chain jumped a few teeth or your pulsar/rotor (metal wheel behind cover with pointy bits) has managed to slip.

MM!

This is a visual metaphor of what happens when a cam chain snaps.

ITS FIXED !!!!!!!!!!!!!
took the pulse cover off and the disc was loose and flapping about like a fat lass at a disco. Tightened bolt and fired up sweet as a nut !

Thanks for all your help guys.......until next time.......ride it like ya stole it !!!

ZXR400 owners.... Always fearing the worst.