I'm a proud-to-be owner of a ZXR 400 ... unfortunately its a grey bike imported from Japan but am determined to get it running well but i need help tho...
I first had a fuel tank problem,it was rusted, so i got that sorted out. Now i ride a while and when temp is up the bike looses power and stalls.. then i have to push... i leave it to stand overnight then it will start in the morning but then same problem occurs!!then i also drained my oil, even tho it had just been serviced,well so the guy who sold me the bike said..it was mixed with fuel and water and lots of sludge!!was told my head gasket is blown thats why water mixing with oil...?????then i was also told that my head might be cracked thats why when the bike is running hot it looses power and stalls...????? i need help please mate...
i've stripped until the head and need to take carbs off and the head as well but how do i go about it?????which markings do i use??PLEASE HELP... i wanna go again...
Definately sounds like the head gasket may have gone. How hot does the engine get according to the temperature gauge? Normal running temperature is upto half way, anything over that and your either sitting in traffic or something is wrong.
We have got the manuals here which tell you about the timing marks
First of all, what model is it? H or L, it doesnt matter for the engine, but it does for other stuff.
Also I'm assuming you have the engine out of the frame? Also before you take everything apart it might be worth ordering up a new set of headbolts and a head gasket from cradleys. I seem to remember there being 8 bolts of one type and 3 of another but cradley will be able to tell you.
If you havent got the engine out of the frame it might be worth doing so, although it can be done in the frame by removing all the engine bolts except the back bottom bolts and then use the drive chain and the chain adjusters to pivot the engine about this bolt, you should be able to get to the head easily then.
It will also be worth you checking out your rocker arms whilst your at it and checking for scoring of cams as the top end doesnt like being starved of oil. It is worth noting that when you remove the cam caps (the bits ontop of the cams) that you should remove them all at the same time at the same rate. This means removing bolts in a criss-cross fashion as decribed below:
Assume that the bolts for EACH cam cap are numbered as follows:
1 2
3 4
When removing the caps undo the bolts as follows, bolt 1 on cap 1, bolt 4 on cap 1, bolt 1 on cap 2, bolt 4 on cap 2, bolt 1 on cap 3, bolt 4 on cap 3, bolt 1 on cap 4, bolt 4 on cap 4, bolt 3 on cap 1, bolt 2 on cap 1, bolt 3 on cap 2, bolt 2 on cap 2, bolt 3 on cap 3, bolt 2 on cap 3, bolt 3 on cap 4, bolt 2 on cap 4. These bolts should be loosened in steps, so that they come off evenly. The caps should just wiggle off the head, but be careful not to apply too much pressure. They come off in one linked up C shape with the oil linkage that sits above the top camchain guide.
Also check valve clearances and balance carbs when your done....
It's all a weekends work and should be all ready to go again by monday.
Cheers
Dan
IF YOU CAM CAPS BECOME DAMAGED IN ANYWAY YOU WILL NEED TO REPLACE YOUR WHOLE HEAD. SO BE CAREFUL.
The bike only goes as fast as you want it to...
...i know, it's great
again... 
