Stop that rattle…
Engine noisy? Your cam chain tensioner could well be knackered
1 Heard a rattle?
The cam chain tensioner (CCT) is a component inside your bike’s engine that ensures the chain runs smoothly at all times. Most tensioners are automatic and operate without fault for tens of thousands of miles. But there are a few models where it’s a bit of a known weakspot, and the warning is a rattle from the top end. Luckily it’s easy to fix.
2 Locate the tensioner
On this Suzuki GSX-R600, the cam chain tensioner is located behind the cylinder block on the right-hand side. To gain access to the tensioner retaining bolts, you may need to remove the fuel tank and a fairing panel. Check a workshop manual for the procedure for your specific bike; on naked bikes there is often very little to remove.
3 Get yourself tooled up
Even with the panel and tank removed, you may find that access to the tensioner, and the two fasteners which hold it in, is quite limited. The best way to get at them is by using a long 3/8 extension bar with a wobbly universal type of drive, in this case combined with an Allen socket on the end. Remember to take your time and note how it all fits together.
4 Release the tension
Undo both bolts half a turn each to start, and then undo them evenly in turn. Due to it being spring loaded, it’s quite possible that the tensioner will have some energy in it, and this will aid removal as it pushes itself away from the engine case. Carefully remove the bolts making sure not to drop them, then ease the tensioner out of the way ready for inspection.
You could also use a T-bar with a 5mm ball-end drive
Do not turn the engine over once the tensioner is removed
5 Clean the case
Inspect the area where the tensioner was located to see if the gasket or part of it has stuck to the case. Remove all traces until only bare metal is showing. If it proves stubborn use a fine blade to scalp it away, taking care to ensure none of the material goes inside the engine.
6 Look at the lengths
Compare old vs new. The difference in length of the tension shaft is because new ones are preloaded and locked with a widget that needs to be removed after fitting. When this widget is removed the hole needs to be filled using the grommet from the old one.
7 Grab the gasket
Fit the new gasket to the new tensioner body using a dab of grease to lightly fix the gasket to the case as you wriggle it into place. Make sure that the tensioner on your bike is installed the correct way up if this is specified in the workshop manual.
8 Torque ’em up right
Screw in the bolts that secure the tensioner, making sure they go in evenly. Then, using a lowrange torque wrench, tighten them up to spec. It’s normal for 6mm threaded bolts to be torqued up to 10Nm, but check the manual for your particular bike.
9 Release the tension
With the new tensioner installed, it’s time to remove the widget that will release the plunger onto the cam chain tensioning blade. It’ll usually need to be extracted using a pair of long-nosed pliers. As it’s removed you should hear the spring thump out the plunger.
10 Take up the slack
In theory the tensioner should take up the slack as soon as the engine starts, but it’s a good idea to make sure the cam chain is fully tensioned prior to start up. To do this, remove the crankshaft inspection cover and manually turn the engine over using a socket.