www.zxrworld.co.uk

Hi people, new to this site, so hello

I have a chance of buying a 1992 zxr400 (Cheap) but it has a bad rattle on the engine. sounds like top end,
increases with revs and rattles when going up in revs and down, does not go if you pull the clutch in ! sounds like an old Vauxhall with the cam worn. I know the lad who is selling it, when he got it the cam chains etc had been replaced but it wouldn't run. after he got it running it was ok (no rattle) the bike has been stored for nearly 2 years now he's selling but when we started it had this rattle
any clues ? all help appreciated
many thanks

steve

need help with this one, now have engine out can't see any wear on cams or rockers, only one slight grove in the (Sorry don't know what you call it) thing that clamps the cams down, anything else that would cause a noise like one of the cam lobes was flat !
Any help welcome

cheers
Steve

Hi steve, it could possibly be the valve clearances causing the noise, or possibly the cam chain.

If you have a set of feeler gauges check the clearances and see whats what. Failing that, get the small cover off the RHS of the motor and check the tensioner, i believe theres a way to tell how worn it is by how far the adjuster has moved, maybe some one else can fill you in on that as ive personally no experience on that level yet.

Might have been worth having a listen to the engine with the bodywork off to see if you could locate more precisely where the noise is coming from.

Rob

many thanks for reply
it sound just like one of the cams lobes is square, but all are ok
the rattle goes up and down with engine speed, does not go away at any revs, which reading post rules out the tensioner right ?
def top end rattle
would using the cam caps from another engine cause rattle ? there are groves (wear) on two of the surfaces not sure what been changed as it has had engine stripped before using a donor enigne to make one good or not so good one

I think that does rule out the cam chain yeah.

I dont know for sure if the cam caps will make that noise, but im pretty sure the caps have to be matched to the engine, and a mismatched one will break afaik as someone had the misfortune of doing that not too long ago.

How you tell weather they are matched i dont know. Theres peeeps here who know far more about that than i do, i expect they will be along shortly to inform you better than i.

thanks, will check on post later Mr stella artois is calling

ZXR's are noisey engines anyway. Could just be that? I remember when I first got mine, I honestly believed it was about to throw a piston out some of the noises it made.

A "rattle" would suggest to me that it's camchain related

Worn rockers or cams would be more of a ticky tappy sound ?

I reckon

cargo wrote:A "rattle" would suggest to me that it's camchain related

Worn rockers or cams would be more of a ticky tappy sound ?

I reckon

Hi,

Dam when my cam chain went, it sounded like a batterd out ice cream truck! As Rob said, take the ignition cover off and inspect the tensioner rod. Right hand side of engine at the front. Undo them bolts and inspect how close the tensioner rod is to the casing. If you're unsure, take a picture and post it on here

TBH I would say the cam chain is nookared. Btw what's the milage on the bike?

Regards

Rich

Its and kind of rattle that makes you want to turn the engine off stright away ! increases with revs does not go away at any rev range up or down the revs
just going to inspect the cam chain tensioner, but I have been told it was replaced but that's only what ive been told
40k kilometers on clock which is genuine old MOT's that shows it
Cheers
Steve

maybe you have an oil way blocked somewhere not allowing enough oil to the cams?,oil pump could have gone?

Often I feel that I've been a little cheeky in how I respond to posts but sometimes it's the only way to tease out the information needed to solve a problem.

Now we find that the cam chain tensioner has been replaced....................that raises more questions...................

Was it done properly ?

The bike sold with this "rattle" could it be that the previous owner botched the cam chain temsioner replacment job ?

Why did he sell it ?
Why was the tensioner replaced ?

Was it rattling before the camchain tensioner replacment ?


etc etc etc

I did say in the first post that the cam chains etc had been replaced
The person had them changed but couldn't get it running as said in first post
I know the person who got it running and there wasn't a rattle (which is the strange part ) but it was just put into his shed for 2 years (No bike test) then I bugged him to sell it (mistake ?) as said in first place
cheers
Steve

To be brutally honest if it started 2 years ago and had NO rattle................then what happened to cause a rattle now.

Could be with sitting so long and then started it suffered damage from having little or no oil in or around the top end.................not really likey IMHO..but maybe just maybe

When it was last started 2 years ago..............did it run for any length of time ? Who declared it rattle free then?

Still think it sounds like a botched cam chain tensioner replacment.

You really need to get the full story in detail .........................try asking the previous owner if he knows how to replace the cam chain tensioner.
Does he understand how a ZXR400 cam chain tensioner works ?

If it was me I'd have the engine out for at least a top end rebuild..................with that sort of milage on it it would do no harm to freshen up the head and valves anyway.

More info, engine has had a complete strip and lower mileage parts used from another engine, chains and tensioner are new from other owner, spoken to the lad who I got it from, he said engine was re-built and it had a rattle from the clutch (not engine rattle) that’s why it was put in his shed.

Important bit! He can't remember when removing the clutch cable if he removed the two bolts that holds it to the engine when checking the clutch

So if the two bolts have been removed the tensioner will need resetting right ?

what damage would it cause if run like this ?

Cheers
Steve