www.zxrworld.co.uk

hey having a problem with my cam chain tensioners, so far the bike has managed to destroy 3 of the bloody things in 6 months. i was wondering whether anyone else has had this problem and knows what the long term solution is. or whether anyone had any ideas really.

i am going to get a new cam chain and a new tensioner and im sure the nike will run fine, however come 2 months im sure it will destroy it again.

Can only imagine that your setting the tension too high? Must be doing something wrong.

do you mean the automatic adjuster or the rubber guides are being destroyed?

Sounds like you are not fitting the tensioner correctly.

I wonder are you resetting the tension before fitting the tensioner body ?

There are two types of ZXR400 tensioner but both work on the same principle.
A spring pushes upwards to press the tensioner blade against the chain however it works like a ratchet once tension is on it does not come back off again.
On a the newer type tensioner there is a bolt and spring that need to be removed before fitting the body to the engine also the ratchet needs to be manually reset so that the tension would be at a minium. Once you've done that bolt the tensioner body to the engine............do not forget the clutch cable bracket.
Now put the springs up into the tensioner body and then the bolt that holds the springs in. This is tricky as the spring wants to push down on the bolt............. as you fit the bolt you are compressing the spring.
When the bolt is in correctly turn the engine over manually with a 19mm spanner or scocket you should hear the tensioner clicking and the spring applies tension to the chain. Turn the engine over a few times and the job is a good un

As for every job tighten everything with a torque wrench to the correct torque as you do it.

thanks for the suggestion cargo, but i have put the tensioner back just as you described each time making sure to reset the ratchet and not to over tighten the bolt, however the tensioner blades have all still snapped, i have an old tensioner unit and am going to fit that instead as it is a bit less brutal in its automatic tensioning.
i think that the cam chain has stretched and am going to be taking it out in a sec to see, if this is the case and it is too big then this would cause the tensioner to go to the top adjustment when reinstalled therefor leaving no room for adjustment. if the chain was still a bit loose and tightened up when i opened up the throtle it would slap the already fully "adjusted" tensioning blade causing undue stress and failure. this is however just a theory please get back to me if you think it viable or not. any help is appreciated at this time.