Zephyr Manual Cam Chain Tensioner

Installing the new manual cam chain tensioner:


  1. You will need a pair of 13mm wrenches, a 4mm hex key (allen head) wrench or socket, ratchet, inch/lb torque wrench, gasket sealer, an appropriate size socket/ratchet to turn over the engine.
  2. You may or may not have to remove the carburetors to do the installation, I had them off so it was no problem. Adjustment can be made with the carburetors on the bike.
  3. Remove the “automatic” tensioner body from the motor by removing the two small bolts.
  4. Remove the Zephyr right side crank cover, easiest side to work from.
  5. Back the adjustment bolt out a fair amount on the new tensioner and remove the plastic sleeves from the mount bolts
  6. Put some Yamabond (Hondabond, Kawabond – whatever bond) sealant or a similar goop on the tensioner gasket. I don’t know for sure, but even grease may work fine.
  7. Install the tensioner in place threading in the supplied countersunk bolts. On the Zephyr just install the tensioner either direction. The adjuster bolt is centered so there is no difference.
  8. Torque the bolts to 72 in/lb (6 ft/lb or 8 N/m) if you wish, I just used a 4 mm allen wrench and my “torque wrench arm”… if you know what I mean.
  9. Turn the adjuster bolt in as far as possible by hand.
  10. Using the appropriate socket and ratchet on the bolt in the end of the crank shaft,

    A)   From the right side, rotate the crank shaft clockwise slowly, which will pull the cam chain taut on the drive side making the tensioner side slack, while turning the tensioner adjustment screw by hand. DO NOT spin the motor over with the starter, you risk jumping cam timing or possible valve damage due to excess chain slack.

    B)   Turn the motor over for a few revolutions while applying pressure by hand, The tensioner bolt will turn in easily when taking up slack in the chain, but will resist turning when either the chain is under tension (turning the crank the wrong way) or when the slack has been taken up.

    C)   You should be able to tell when the slack is gone, the bolt will no longer turn easily.

    D)   Back off 1/6 turn (one flat of the acorn nut).

    E)   Using one 13mm wrench snug the tensioner locking nut down tight while holding the acorn nut with the other 13mm wrench.

    F)   Rotate the crank slowly over again to make sure valves are not out of time and hitting the pistons.

  11. Start the engine and warm it up to operating temperature.
  12. With the engine running, listen for any chain noise.

    A)   Tighten the tensioner bolt back in slightly (about 1/8 turn or less) until rattle is gone.

    B)   Tighten the locking nut while holding the tensioner nut in place with a wrench to keep it from turning.


This works without gimmicks and guesswork that can over tighten the chains or let them flail around in the cases. Re-adjust every several thousand miles or if you hear the rattle of cam chains again. I think I’ve only done about 4 adjustments over the past 25,000 miles using the “sound” method on the KLX. I didn’t need any change in adjustment on the Zephyr after installation. The key point is what the tensioner does – it simply takes up excess slack so the chain(s) don’t slap around and wear prematurely. There is no preloading necessary.


Install the tensioner and take out the slack by turning the crank while tightening the adjuster nut by hand.

Take off the right side crank shaft cover and rotate the crank shaft clockwise using a 13 mm socket and ratchet or breaker bar.





Copyright © 2009 Krieger Cam Chain Tensioners
Last modified: 08/19/12