Replace of the distribution chain
Because my bike had run about 110.000 km it was getting time to replace the distribution chain. Maybe it wasn't necesary but it can give a hell of a mess if the chain brakes because the pistons can hit the valves.
The replacing of the chain is quite a though job and luckily I had help from someone who did this before and knows much more about working on engines than I do.
I will describe how it is done so you can decide wether to do it yourself or to let it do by a shop.
- Get the following parts at your dealer: distribution chain, chain tensioner, tensioner spring, gasket and oil seals for the distribution cover (crank shaft and cam shaft).
- Remove the lower fairing en the ignition cover. I dismounted the complete exhaust system in one part and lower them to get some working space.
- Remove the centrifugal regulator, the rectifier plate and de stator from the dynamo.
Make notes of all the connections so you can place them back easily.
To remove the chain cover you also have to disconnect the wire of the starter relay and unfortunatelly you have to remove quite a few parts to reconnect it like the gas tank, the ignition coils and the cover of the starter engine.
- Remove the special inside hex bolt from the dynamo rotor and than the rotor itself with a special remover tool. The rotor is put on the crank shaft with a conical fit. The removal tool can be made by yourself from a piece of firm iron tube with fits over the rotor. The tube must be closed on one end with a hole in the middle. The other end must have three notches so it fits well on the distribution cover. Also you must have a bolt and a nut to pull the rotor off. Click HERE for a photo of the remover tool (the arrows indicate the notches). Put the tool over the rotor and screw the bolt, with the nut screwed on it, inside it. By tightening the nut the rotor will come off.
When it doesn't come off give it a few hits with a hammer. (I hope my english translations of this part will make you understand what I want to say ;-)
- ALTERNATIVE METHOD TO REMOVE ROTOR: In my guestbook Paul wrote a smart tip that doesn't require the special tool. Take a round hardened steel pin of 5mm with a length of 50mm. It's also possible to saw an old 5mm allen key to 50mm length. remove the inside hex bolt out of the rotor, put the pin in the hole en put back the bolt. Because the pin is inside the axle the bolt will screw into the rotor but will not reach the thread of the axle. Tighten the bolt and hit the end of it a few times. De rotor must come off now. Thanks paul for your tip.
- Remove the distribution cover.
- The chain is visible now. Remove the chain tensioner. The removal of the chain is hard because the original chain is in one piece so you have to cut it through.
- BEWARE THAT BOTH CHAINWHEELS STAY IN POSITION AFTER THE CHAIN IS REMOVED, MARK THEM !!!
When the new chain is mounted and one of the chain wheels is turned a bit the engine will run very bad when you are lucky, when you're not lucky the pistons will hit the valves and will give a mess.
- Put the new chain in place. The most annoying job is to put the link between the chain ends because the locking spring has to be put on the rear of the chain and there is very little space. (FOTO)
- When the chain is placed at last ;-) the new tensioner and tensioner spring can be mounted.
- Remove the old seals en replace them by the new ones.
- Clean the engine and the distribution cover. Remove all of the old gasket and do it well because in my case it was leaking oil after a few months so I could start right over.
- Put a bolt in de crank shaft and turn the engine a few times so you know for sure that the pistons don't hit the valves. When you made a mistake putting on the chain it will run bad in the worst case put you will know before starting the engine that the valves an pistons are safe.
- Mount the distribution cover en remount the rectifier, rotor and stator and also reconnect the cabling.
- Check if the engine runs ok and if it does go on with remounting. Also mind the battery light in the cockpit, when it lights above 1000 rpm you know you've done something wrong.
(c) W.P.Barendsen 2002