Hi all....I have a 1 year old 900cc T100 water-cooled Bonnie. Around the time of its first oil change 500miles.....I noticed a tapping/rattle sort of noise soon after a cold start...not right away but maybe after is been idling for 20seconds. Only lass around 30 to 45 seconds and then is gone till the next cold start. I am starting to think maybe the hydraulic cam chain tensioner is leaking its oil out over night....the oil inlet is tiny so it will take a time to re-fill.....over course I maybe well out with this idea....the dealers tech guy said no idea whats causing it....just ignore it as its not there all the time. Its so easy to get the tensioner out....but the Haynes manual say the cam needs locking before the tensioner is removed. Does anybody know if its strictly necessary to have to lock the cams. I know that if the engine was turned with the tensioner removed....the chain could slip and balls up the valve timing. Or is there more to it that I have not realised? I dont want to disturb any more than necessary being a brand new engine....and dont have a lot of confidence in the local dealer. Nick in the UK.
The tensioner has a spring clip in it so when the oil drains out it still remains under tension. It will click into the next groove as the chain slackens, think of it like a ratchet. It could be the chain has gained a little slack but the tensioner has not yet clicked into the next position. I reckon your fine, it will lock into the next position eventually.
I sometimes get the rattle immediately after startup, hot or cold on the Street Scrambler (same engine). Doesn't do it every time and only lasts a second or so but when it does it sound like something is amiss. I was a little concerned when I first got the bike until I found out it has a hydraulic tensioner. I've had the same thing on other bikes, it's nothing to worry about IMO.
