Just downloaded. I generally do a oil change, brake fluid, and coolant flush no question when I purchase a bike. The chain, sprocket, and filter were just replaced before I purchased it (seller provided receipts for repairs). I should have a weisco shim kit on the way shortly to minimize down time. Im not experiencing any abnormal noises but Im thinking about replacing the chain tensioner as preventative maintenance (oem/aftermarket?). Thanks for the advice
The auto tensioner uses a ratchet and pawl design that has been in use with clockworks since ~ the 17th century. The spring assembly pushes against the shoe, with takes up the slack on the timing chain. The ratchet takes most of the pressure off of the spring, so it can be very light/low pressure.... the holding power is the ratchet assembly.
Works as a one way extension, rather than allowing motion both ways.
The nice part about the OEM setup, is that it would be very difficult for it to put too much tension on the chain. The gap the spring consumes, is all the slack it can take up.
When the motor accelerates, the timing chain will flop about a bit with changes in load.... engine compression puts a different torque on the drive line, compared to acceleration. That flopping, is all the slack there is. Since the chain sits inside the motor, without exposure to the elements (dirt, water, etc.) the rate of wear on the links of the chain is very low. It won't stretch much due to wear between the pins and plates at all. Probably good for the life of the motor, even with poor maintenance.
A manual tensioner allows the owner to apply as much pressure to the shoe that takes up the slack as they desire. These are FREQEUNTLY over tightened. If they are, the chain will start to cut into the chain guides that route the chain between the crankshaft and the cam shafts. When they cut into the material, that will make the chain loose.... which means the cycle has to repeat, if you want the thing to remain quiet. Who knows how long it will be, before the chain cuts all the way through the guides......
But I can tell you that it will almost certainly require dropping the motor out of the frame to replace them.