Cam caps - removal procedure

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Moonfire
zxr400 oc member
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Joined: Mon May 02, 2011 5:40 pm
My Bike: ZXR 400

Cam caps - removal procedure

Post by Moonfire »

Hi,

I'm just about to remove the cam caps from an L3 in order to fit a new timing chain and have read about the importance of taking the torque of each successive (cap) retaining bolt a little at a time in order to avoid stressing and cracking the caps. Is there a sequence to doing so?

In other words do I start at (say) the inlet cam cap on the left hand side and begin to undo the two diagonally opposed bolts on that cam cap and carry on and do the same with the other two bolts on the same cap, or do should I do the first two and then move on to the next cam cap and then go back to the first and do the remaining two? Then, when they are all loose move on to the exhaust cams and follow the the same procedure?

Sorry if this is over thinking things, but I realise I'm going to get one shot at this and so thought I should check before I start.

Grateful for any advice please.
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banner001
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Re: Cam caps - removal procedure

Post by banner001 »

first thing i do is remove the chain tensioner so there is a bit of slack in the chain and its not being pinched down by it.

then start by undoing every bolt 1/2 a turn in a criss-cross patern:
i.e.
9-5-1-3-7
8-4-2-6-10 etc. i do this for the inlet side and then the exhaust.

this will break the initial seal, i then proceed in the same criss-cross pattern but do 1 full turn until you can start to see some large gaps appearing between the cam covers and the head, and then i start to turn them 2 turns at a time...have never had a problem and i think my method is overkill, ive seen people just undo all the bolts a little at a time, and then turn the tighter ones until they become loose and keep moving onto the tighter ones...

have a look at the guide of how to change the timing chain and get it reset back to the correct timing with a new chain and you will be golden.

i would also have a look at the timing chain guides whilst you are in there (though the inlet side one requires you to remove the engine or at least tilt it in the frame) for excessive wear/breakage/chunks of plastic missing, and also have a look at the power and general condition of your chain tensioner to make sure its functioning as intended...its one more job out of the way then.

when you reassemble exerything make damn sure that your exhaust cam cover nearest the chain is fully situated in the oilway...a common problem is that people dont locate this, or check that its not moved when reassembling the covers and its only aluminium, if its out of alignment or not situated correctly when you come to start screwing the covers back down they have a tendancy to break...and thats not good news as you end up having to do this (i didnt do this, its a stock photo btw...):-
Image
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
Moonfire
zxr400 oc member
zxr400 oc member
Posts: 20
Joined: Mon May 02, 2011 5:40 pm
My Bike: ZXR 400

Re: Cam caps - removal procedure

Post by Moonfire »

Fantastic - thanks Banner, very much appreciated.
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