Cam Chain Tensioner Extenders Installation

[Cajunrider]

At the KNOW Session hosted by Billmac and Cheryl, we installed the cam chain extenders on SteveO's 2004 Nomad 1500. Installation on the 1600 is the same. I attached the link of the step by step installation starting with a picture of Steve's fine looking 1500. I would have preferred attaching individual pictures but there are quite a few which would have made this thread several pages long. We started with the (easy) rear cylinder tensioner. I removed the right side cover allowing more room to get my hand behind the rear cylinder header pipe. It is not necessary to remove the rear header pipe. I then loosened the tensioner lock screw which is facing directly at you on the side of the tensioner assembly. Place a rag on the engine below the tensioner to catch the capfull of oil that will spill out when the cap is unscrewed. The cap threads are very fine making the removal very long winded. Everything inside is under spring tension so be carefull as you get to the end of the threads not to let the cap pop off with the bearing, bearing retainer, and springs flying everywhere. After the cap and internals are removed, keep the bearing orientation the same for reassembly. I've never measured the bearing dimension with a micrometer but I've read that it is slightly tapered. Steve cleaned up the bearing, retainer, and springs while I measured the travel before removing the assembly. The push rod end was recessed nearly 3/8" below the end of the assembly indicating it was out of travel. Remove the assembly and carefully scrape any gasket residual left on the engine and assembly sealing surfaces. Depress the hinged ratchet end allowing the push rod to be retracted back into the assembly. Go back an forth with it familiarizing yourself with how it works. Rather than cutting the OEM push rod "donut" off as Gadjet describes, we used a couple of open end wrenches on top of the vise and a bolt and ball peen hammer to remove it. Just a couple of taps on the end of the push rod with the wrenches backing up the donut allowed it to pop off. Be carefull not to drop the assembly when the donut pops off. Sorry but we forgot to take pictures of the extenders replacing the donuts. We were pretty excited that they came off so easily without cutting them. Put a drop of high temperature red loctite in the Chuckster extender and twist it onto the end of the pushrod until it bottoms out. If there is a tight spot when you are twisting the extender onto the rod, stop there. Allow the loctite to set for 1/2 hour or so before attempting to install the assembly. Install your new o-ring onto the assembly. To set the tensioner, fully retract the rod into the assembly. Make certain that the side lock bolt is loose enough to be flush with the inside of the assembly. Drop the big spring into the assembly and the bearing over the spring. Use a flat blade screwdriver to compress the spring by pushing the bearing down into the assembly until it is past the lock screw. Run the lock screw in finger tight above the bearing to hold the spring compressed. Install the new gasket and tensioner onto the engine and tighten up the two bolts. I did not torque them on. I used the short end of the 90 degree 5mm allen wrench and tightend them firmly using 2 fingers near the long end of the wrench. On the rear cylinder, the shoe that holds tension against the chain flops back against the opening when the tensioner is removed. Gently push the rod with your finger until you feel resistance. This will do some of the preliminary work for the skinny spring that fits into the push rod. Install the skinny spring, bearing retainer and cap and snug it with the combination wrench. Loosen the side lock screw until you hear the bearing snap into the retainer. Tighten up the lock screw and you are finished with this tensioner.
Now, for the tougher one. It is only tough if the intake crossover duct is still in place. Loosen the two duct screws holding it to the backing plate behind the right side dog bowl. Remove the left side dog bowl, filter, backing plate and bracket. Be careful not to lose the square nuts that are inserted into the end of the intake crossover duct after you remove the two screws. You should be able to wiggle the end of the crossover being able to lift it until it contacts the intake manifold. This will give you access to the rear bolt on the tensioner assembly. Follow the same cap, spring, bearing and retainer removal instructions as for the rear cylinder assembly. Only difference is no oil will pour out of this one. Again, be carefull when the cap gets loose so the internals dont fly everywhere. Forget about measuring travel on this one. You can't get a measuring scale in there. Loosen the bolts and use the ball end of the hex key to spin out the inside bolt. Wiggle and turn the assembly until you get it out. If the old gasket remains on the engine, be carefull not to drop any pieces of it into the opening when you are removing it. You could stuff a clean rag in the hole leaving just a tail hanging out for easy retrieval. Install the extender as noted above and set it the same as the other. Use the 90 degree end of the wrench with a little grease on it to hold the inside bolt. Stab the bolt and run it in with the ball end. You will probably have a few choice words for the crossover duct but it really isn't that bad. Snug everything up and install the cap, retainer and small spring. Don't forget to back the lock bolt out to hear the "snap" and re-tighten it. Crank it up and let it run for a few minutes to be sure you don't have any oil leaks before putting all of the hardware back together. You're done. Enjoy the quieter engine and peace of mind. If you have any questions on something I may have missed, send me a PM.

http://s300.photobucket.com/albums/n...n%20Extenders/

[trip]

From experience, some personal insights on cam chain tensioners.

Although almost everyone who has checked or extended cam chain tensioners has done so with minimal problems, I don't think the potential for problems should be under-estimated. Things can go wrong very easily, as they did for me. If they do and you are lucky, you'll only need to pull the engine, take off the rocker cover and rocker case, re-time the chain, and put everything back together again. Figure 40 man-hours plus gaskets, etc. And hope you live relatively close to Mac. If you're not lucky, it could be catastrophic engine damage. It's not clear if the valves can contact the pistons in our bikes.

The things to avoid are:
1) Don't ever loosen the screws holding the tensioner body to the the jug and then retighten them. When you loosen the screws, the tensioner will extend. When you re-tighten them, the tensioner can't retract, and will therefore overtighten the chain. The tensioner must be removed and reset if the screws are loosened.
2) If you remove the cap to check the tensioner, don't accidently push the rod into the body further than the spring automatically has pushed it in. Otherwise, you will again overtighten the chain.
3) If you remove the tensioner, make sure the rod is fully retracted when you are re-inserting it. Don't accidently push it in while you are inserting it. However, once it is inserted and fully seated, gently push it in until it contacts the guide so that any slack in the chain is taken up, preventing any chance of the chain slipping. Don't push it in too hard though or you risk overtightening the chain.
4) Don't remove a tensioner without first insuring that the related cylinder is at top dead center on the compression stroke. Otherwise, an open valve can close under the pressure of its spring, spinning the camshaft and slipping the timing. Important to note that there is absolutely nothing that prevents the chain from slipping on the gear other than gravity and friction, neither of which are guarantees in this situation.
5) After the extenders are added, I would recommend spinning the engine several times by hand to insure that everything is working correctly before spinning the starter. This is easy to do if you followed step 4 above by pulling the left side cover and removing the cap over the timing marks and the nut on the end of crankshaft. Insure the crank is spun counter-clockwise, or you risk upsetting the timing.

Note: If you loosen a tensioner and there is a lot of pressure pushing it out, then the valves are open and the chain is under tension. Same applies if you are putting a tensioner back in, and you have to push hard to get it in. If that happens, do nothing to disturb that chain while the tensioner is out, or you risk slipping the chain. Get the tensioner back in as quickly as you can. Better yet, follow step 4 above. If you hear a short whirring noise and the tensioner then goes back in easily, the chain has slipped and you will need to pull the engine to reset it.

Note: Although it isn't foolproof, there is a way to determine if the valve timing may have slipped by removing the spark plug tubes. If you do, you can see the very bottom of the camshaft gear. You will need a bright light, and a small mirror is helpful. If you spin the engine by hand, you will see the following marks appear at the bottom of the gear: an F or an R (front or rear jug) with a line and a paint mark, an F or an R, and a line. You will also see an F and R appear in the timing window. Spin the engine until the F appears in the timing window. Then look for the F on the bottom of the gear for the front jug. Don't confuse the F for the F with the line and paint mark. If you don't see it, spin the engine until the F appears again in the timing window. You should then see the F on the bottom of the gear. If you don't see it either time, you may have a problem. It should appear every other spin of the crank. When you see it, the piston should be at TDC exhaust. When you don't, the piston should be at TDC compression. Do the same for the rear cylinder, but look for an R instead of an F.

Note: All the above applies to a 2008 Nomad 1600. Not sure how it relates to 1500's.
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Tom Maziarz (tomm)
Kawanow #00766
2008 Kawasaki Nomad (Black)
1978 Suzuki GS750EC
1974 Honda CB360T