zxr400 making a funny noise

[hendo1990]

i used my bike on wednesday to go to uni and the shops and it was fine and dandy all was well. however when i came to go to uni on it on thursday i fired it up with a bit of choke when i knocked the choke off to let it idle there was a very consistent tapping/knocking noise coming from the top end and then the engine cut out. i started it again and the same thing happened so ive left it. when it cut out the 1st time a fair bit of smoke was coming out of the exhaust after it stalled. sort of like when you see someone shoot a gun ina film and wisps of smoke come out the barrel (thats the best way i can describe it) there was also a tick sound immediatley after the engine cut out which it has never done before. does anyone know what could be wrong? any help would be appreciated.
thanks
John

[lewisdale]

have you checked youre oil and water?
coule be tapping/rattling due to no oil or due to getting very hot due to no coolant, could even be poss head gasket!!

[CaNsA]

My money is on the head gasket. Only cos mine had the same symptoms. Get the value clearances checked too.

[cargo]

I'd be looking at a few other things before even thinking about head gasket.

In fact I'd go so far as to say that so far there is no evidence whatsoever to suggest a head gasket problem

[lewisdale]

HEAD GASKET GONE=WATER GONE=OVERHEATING=OIL GOES VERY THIN=RATTLE,TAP
THATS WHAT I AM SAYING IS POSSIBLE,

[extonyg]

what about cam chain,chain guides, chain tensioner, exhaust blow or valve clearances..........

[cargo]

valve spring
rocker
loose spark plug
loose bolt generally
bent valve
dropped valve

but please by all means get stuck into replacing the head gasket you'll see lots of the other possibliites as you do it

Water gone ?
Where did he say anything about losing water ?? ??

Over heating ? where did he say anything about over heating ?

Best advice I can give is to be very careful about taking advice

[lewisdale]

i said if the water has gone, read carefully, it was only a suggestion, like youre suggestions, something to check and look out for :wanker

[cargo]

i said if the water has gone, read carefully, it was only a suggestion, like youre suggestions, something to check and look out for :wanker

[lewisdale]

LOL !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[hendo1990]

i tried the bike again today and it fired up ok with the choke on. I left it on choke for a bit then knocked it off and it was still tapping but it didn't cut out this time. i let it idle for a while and when the engine temperature went up the tapping went away and it sounded fine. I recently changed the oil and filter and the filter they gave me was only a cheap one. (i checked the oil and water and theres plenty in and doesnt appear to have lost any) The one previously on the bike was a genuine Kawasaki filter could this have anything to do with it?
cheers for the replies
John

[lewisdale]

what quality oil did you put in it?

[cargo]

i tried the bike again today and it fired up ok with the choke on. I left it on choke for a bit then knocked it off and it was still tapping but it didn't cut out this time. i let it idle for a while and when the engine temperature went up the tapping went away and it sounded fine. I recently changed the oil and filter and the filter they gave me was only a cheap one. (i checked the oil and water and theres plenty in and doesnt appear to have lost any) The one previously on the bike was a genuine Kawasaki filter could this have anything to do with it?
cheers for the replies
John

From a personal point of view I don't like " cheap" oil filters and would never use one.
Having said that I would imagine that if a cheap oil filter was going to contribute towards engine damage then it would occur over a period of time and not overnight.
So when you next change the oil use a genuine Kawasaki filter.

Now back to your tapping noise.........................you say the noise faded when the bike warmed up.....................that gives a clue as to what it might be be.
When metal gets warmed it expands this is a fact (and nothing lewisdale says can change it).............so I'm guessing that somewhere in or on you engine a tapping noise is going away as the metal expands to take up the space between the two components that are doing the tapping. There is within every engine a gap the must be maintained at a specfic distance so as to allow for expansion due to heat. If that gap is on the large side due to wear and tear then a noise can develop especially when it is cold...................expansion occurs as the engine warms and the gap closes and the noise fades.........................

I'm not saying this is definatly what you problem is it is just a suggestion that seems to fit with the symptons you describe...................it is not a wild guess.

But in your search for the mystery noise I'd have a look at you valve clearances........and check them......................all sixteen in fact.............................even if you find them all to be correct it's a job that needs done from time to time anyway and while your doing it you may find something else in the valve gear that is the source of yoour noise.

IF it is a valve clearance problem and you ignore it it will get worse and over time will do even more serious engine damage and ultimatly engine failure

You could of course just change the head gasket .............................(note sarcastic tone)

[hendo1990]

cheers for the replies, the thermal expansion of component as the engine warms up seems to be the most logical explanation. when i get it home i'll have an investigation. to do valve clearances is it just a case of removing the valve and lapping it back in or is there more to it than that?
cheers
john

[cargo]

cheers for the replies, the thermal expansion of component as the engine warms up seems to be the most logical explanation. when i get it home i'll have an investigation. to do valve clearances is it just a case of removing the valve and lapping it back in or is there more to it than that?
cheers
john

No its much easier than that.........I'm sure there is a how to do it guide somewhere on the forum...............