Is it time for a new timing chain?

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nettns
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Joined: Tue May 03, 2016 1:03 pm
My Bike: ZXR400 L2

Is it time for a new timing chain?

Post by nettns »

I've been getting a rattle at 3500rpm. Its not present below or above that speed, it only becomes noticeable at 3500rpm. Today I pulled off the cover and re-seated the tensioner. The tensioner seems to operate fine, but the rattle is still present. I noticed that the timing chain guide pushrod is touching (or very nearly touching) the engine case. I also noticed that the attached lever-arm of the timing chain guide is touching (or very nearly touching) the engine case.

This would lead me to think that the tensioner is actually in its maximum position and that I need to change the timing chain. But I've seen some other posts where the tensioner is extended far beyond where mine is, so I'm not sure. If someone could offer some advice, I'd appreciate it.

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banner001
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Re: Is it time for a new timing chain?

Post by banner001 »

if your tensioner is butting up against the engine case then its time for a new chain. there is a good guide on here of how to do it, you will need to do your valve clearances afterwards, that should sort out some of the rattles.

make sure to inspect the condition of the tensioner blades, if they are looking excessively warn then you might want to change one or both blades, also check the condition of the tensioner blade where it contacts the tensioner pushrod as the metal eyelet can crack or become broken and detached from the blade.
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
nettns
Posts: 5
Joined: Tue May 03, 2016 1:03 pm
My Bike: ZXR400 L2

Re: Is it time for a new timing chain?

Post by nettns »

Excellent, thanks! I'm building a part's list now to get everything sorted out for Spring. The bike is new to me, so I'm not sure how well it was maintained in the past. I think I'd rather be safe than sorry with my repairs.

I'm thinking I will do the following:
-Replace the timing chain
-Replace both timing chain tensioner blades
-Replace or rebuild the timing chain tensioner (at least replacing the piston spring)
-Check valve clearances
GeorgeMoroz
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Joined: Wed Apr 12, 2017 2:21 pm
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Re: Is it time for a new timing chain?

Post by GeorgeMoroz »

Is it normal for a cam chain to have tight spots like a drive chain? Im fairly sure i need a new one too but the one i have is really tight in some places and fairly loose in others
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banner001
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Re: Is it time for a new timing chain?

Post by banner001 »

No, the chain should have a uniform consistency along its length. Is there any visible signs of wear/damage/rust on the chain?

Are you sure it's the chain, and not caused by differences in forces as the crank/cam's are rotated? I.e. have you taken the chain off and checked for tightness or is it still on the bike and under tension?
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
GeorgeMoroz
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Joined: Wed Apr 12, 2017 2:21 pm
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Re: Is it time for a new timing chain?

Post by GeorgeMoroz »

No signs of wear, the chain will go loose when theres no load on the engine (no cylinders compressing) and the crank turns easily. I've taken the chain out and measured it like the manual by hanging it between 2 nails at 20 links apart, and hanging 5kg of weight then measuring the distance, seemed to be fine
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banner001
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Re: Is it time for a new timing chain?

Post by banner001 »

if you still have tight spots when the chain is out then you need a new one.

http://www.kawasakioriginalparts.com/ro ... country=GB

£32 for L1-L9 cam chain 92057-1427
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
GeorgeMoroz
Posts: 10
Joined: Wed Apr 12, 2017 2:21 pm
My Bike: ZXR 400 L3

Re: Is it time for a new timing chain?

Post by GeorgeMoroz »

Thanks got one today, should i be wary about running it in?
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banner001
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Re: Is it time for a new timing chain?

Post by banner001 »

nope, can just hit it hard from the beginning :D

you will need to check your valve clearances once you have fitted the chain, and it would be prudent to check them again after a few hundred miles. make sure to check over the guides and the chain tensioner while you are in there.
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
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