www.zxrworld.co.uk

hello, I have just noticed a piece is broken on one of my cam shaft caps, It allows oil to leak as its where it joins onto another piece, it is the front facing left one. Should I replace it, or is it ok leave as it is? the o ring seal is showing and oil can get threw the break. I have been trying to upload pictures but it saying they too large.

If the oil is still getting to all of your cam shafts further downstream then you are ok, but it's not a good idea to leave it that way as you don't know when it's going to get worse.

Unfortunately the cam covers are line bored to the cylinder head, so if you change the covers you should do so with the matching head, I.e. Replace them both at the same time. If you choose to just replace the cam covers I would get some plastigauge and measure to oil clearances to make sure your still ok.

I would also be wondering where the broken bit of metal is...

ok, I found the broken piece, I have some old cam shafts and a set of matching covers, if I swap them all over would I be ok?
do you know the clearance measurements?

ill state it again, the cam covers are line bored to the head, if you change the covers you should use the matching head too as thats the only way to be 100% sure that the hole thats been bored through the cam covers and through the cylinder head is perfectly round. if you missmatch covers and heads there is a chance that you will end up with a hole between the two that is not perfectly round - exaggerating this the hole could either be slightly figure of 8 shaped (i.e. pinches in at the interface point) or slightly rugbyball shaped (pinched in at the top and bottom)...its got nothing to do with the camshafts.

the only way to know is to do it and use some Plastigauge PL-A, you can buy it from ebay, its a thin strip of a clay like material that deforms under pressure, you measure the width after its been torqued down properly and that gives you your oil clearance.

oil clearances are here:
http://www.zxrworld.co.uk/Manuals/L%20M ... er%204.pdf

listed as "camshaft, camshaft cap clearance" notice that there are 2 different sets of measurements (A and B, shown on the diagram on that same page).

I had a similar problem. First, do not drive the bike with it, you risk loosing oil pressure and messing up your cam journals and cam bearings in a big way, which is what I had from the previous owner. Now for the repair: If it is just a small chip you can try to get it welded back on, and redrill/ream the connection point. If it is seriously fecked and can not be welded, you can fit the old cylinder head with caps from another zxr 400, but you will need to get the flat surface of the caps skimmed to make them sit lower. That will efectively make you cam bearing diameter smaller and then you have to get them line bored to the correct spec or to the specific diameter of your cam journals. Depending on where you live, this may still be cheaper than buying a new head. Your camshafts will be sitting lower, but you can get thin shims to make up for the difference. I did this, it works, but is a lot of work if you do it on your own.

I had the exact same problem a couple of times. As stated you will have to get it repaired. I got mine welded at a local shop, and it held for the rest of the time I had the bike!