CAM CHAIN REPLACEMENT

[samantha]

Hi i coppied the step by step but i dont want to get started without all the info this is what i have so far

WHAT DO I NEED TO ADD / REMOVE please xx

1. Get your ZXR400 somewhere nice and dry, if you have one, a rear paddock stand makes it all nice and steady (easier to work on then). Remove the right hand fairing.


2. Remove the rider's seat, fuel tank cover (at the front) and fuel tank.


3. Remove the airbox.

4.Remove the carbs and HT coils and caps (remember where they go/which side they live!!)

5. Remove rocker cover with 10mm spanner.


6.Having removed the RH fairing and coolant reservoir, remove the timing cover.

7. Before removing the cam chain tensioner set the timing of the pistons so #1 and #4 are at TDC the FT (on the plate) should be facing towards the rear of the bike, this means that the chain won't jump any teeth. (the T's should line up with the gap between the crank cases)


8. Before removing the cam chain tensioner housing, I find it easiest to remove the spring and bolt before hand. So with the tensioner still in place use a 12mm spanner to undo it. After doing this undo the two 5mm hex bolts, and wiggle the tensioner out. Once out reset the cam chain tensioner so its ready to go straight back in on reinstallation.

9. Remove the timing plate, using a 6mm allen key and a 19mm spanner. Use the ring spanner to stop the crank turning as you undo the 6mm hex head. Make sure you dont move/allow the crank to turn.

10. Going back up to the top/cylinder head now..... carefully/evenly/slowly undo the cam cap covers using a 10mm socket, you will also need a 5mm allen key to undo the top cam chain guide (2x5mm hex heads). Check the position of the timing marks on the cams now. I used a tyre marker to highlight this for myself.
My timing marks are facing outwards, so i will put the new cam chain in with them facing outwards, i also made a few extra marks to help me on installing the new chain. (I dont think it matters if they are facing in or out, just try to reduce the opportunity for error, by putting things back together as they came apart). Having done this remove the cams.

11. With the timing plate removed you should be able to see the end of the crank, and the lip protruding out of the crank case which stops the chain from dropping down! :@

12. Remove the front cam chain guide (by pulling on it from the top), and cover the area with rags as shown.

13. Whip out your Dremel/grinder! Also this is where the magnetic stick comes in handy, as it will hold the cam chain from falling down and getting in the way of your grinder.

14. Slowly grind about 1mm to 2mm of the top of the lip off (underneath the cam chain, nowhere else!). Whilst doing this keep checking to see if the cam chain will come out, you dont want to take more than is neccessary off. MAKE SURE YOU THOROUGHLY CLEAN THE AREA BEFORE YOU DO ANYTHING ELSE! (to get rid of all the shavings)

15. Once the old chain is removed, its fair to say a new one will go in! (as long as there was no yanking, heavy/hard pulling to get the old one out!)
IMPORTANT! now check the length of your new chain against the old one!!!! There's little point trying to install the wrong chain if it isnt going to fit!

16. Having done this, feed the new chain from the top down, slip over the crank at the bottom and install the cams.
Installing the cams is the tricky part now.Firstly check the position of the crank again to make sure #1 and #4 are at TDC. I found it easiest to install the exhaust cam first (EX), then install the inlet cam (IN). You may have to do this a few times jiggling it about/moving them round a tooth or two, until the timing marks on the cams are where they should be. (In my case i wanted them to be facing outwards).

17. Make sure when you replace the cam caps/covers you do it slowly and evenly, otherwise you'll end up with a damaged cap/cover and you wil have to replace the whole head and cams!!!! They need to be torqued up to 12NM.

18. Simply replace everything you removed in reverse order, sorry I cba to type out how/what to replace, my fingers are tired now.
ont want to start without asking for further input

[Mori Man]

Before taking the cams off and while at the timing marks do a valve clearance check and write down the gaps.

When cams are out check what size of shim is in each one and write that down corresponding with the gaps, if any are out of range see if you can swap shims about to adjust otherwise order the ones you need.

Exhaust cam HAS to go back in 1st with the chain pulled taught onto the timing mark , the additional chain slack is taken up on the inlet side by the tensioner - you have to count how many rivets there are between each timing mark on the cam sprockets.

Buy a genuine cam chain - the original held you could so get another.

Before doing any grinding make sure there is no way for debris to enter your engine , consider buying either a magnetic sump plug or an oil filter with a magnet in it just incase the worst happens !

Make sure your tensioner blades aren't worn - very easy to see tracks in them, replace as necessary.

DO use new tensioner body spring and pusher - thes eget tired too.

Get a new gasket for your pulsar cover.

Cant see why you need to remove carbs - done my shim check with them on .

Take your time , there is no need to rush.

Good luck and keep us posted on how you fair.

MM!

[samantha]

thanks xxxxxx

[JulianWerner]

Hi Guys, excellent tread

I feel a bit stupid, i did not find this one before i took my old cam chain off, and now its off, and im waiting for the new one.
The reason i am changing the chain is because the tensioner blade is almost fully extended.
And when i tried to do my valve check (first time) the crank / rod ( with the "tooth wheel" in the end ) did not line up like it should, so i also suspect the timing is off or something.

Now i have the old chain off and i am feeling stupid, how do i install the new one ?
The wheel with the T mark, moved when i took the old chain out, so the engine is no longer at TDC.

everything is out / off now, and how do i line up the timing and the crank rod , and then put the chain in so i can do valve check / adjustment ?

A little bit scared now ... heheh
I really hope you can help me .

Thanks