Cambelt tensioner bearings - Page 2

utopia · 25-02-2020, 11:12 PM

When I first bought my 750, I had an issue with belt dust in the covers.
The bike had only done 2000 miles at the time and was on its second or third set of belts.
I discovered that the outer belt was rubbing against the pressed steel washer fitted as an outer flange on the double belt pulley.
This was rubbing away the belt teeth and allowing the belt to migrate outwards where the remaining, toothless portion of belt was bandsawing its way through the plastic belt cover.
It had almost completely cut away a small section of the plastic cover, which was about to drop off and foul between belt and pulley, potentially causing unthinkable damage.
I deduced that the pressed steel washer/flange had been fitted the wrong way around, leaving its sharp edge facing towards the belt instead of the more rounded edge.
I smoothed this off with a needle file and have had no further trouble in the subsequent 27,000 miles.
Dunno how relevant this is to your situation but I thought it worth passing on the info and you can investigate and analyse accordingly.
I assumed at the time that my bike had been fitted with a faulty pulley where the washer/flange had been fitted the wrong way round.
Another forum member reported the same issues at the time, as I recall.

MotoNik · 26-02-2020, 08:37 AM

That sounds horrifying!

Just received new tensioner pinch bolts, wavy washers, and e-clips for the tensioner bearings, so the new belts can go in tonight. Very excited!

25-02-2020, 11:12 PM	#1
utopia No turn left unstoned Join Date: Jun 2010 Location: leicester Bike: M750 Posts: 4,545	When I first bought my 750, I had an issue with belt dust in the covers. The bike had only done 2000 miles at the time and was on its second or third set of belts. I discovered that the outer belt was rubbing against the pressed steel washer fitted as an outer flange on the double belt pulley. This was rubbing away the belt teeth and allowing the belt to migrate outwards where the remaining, toothless portion of belt was bandsawing its way through the plastic belt cover. It had almost completely cut away a small section of the plastic cover, which was about to drop off and foul between belt and pulley, potentially causing unthinkable damage. I deduced that the pressed steel washer/flange had been fitted the wrong way around, leaving its sharp edge facing towards the belt instead of the more rounded edge. I smoothed this off with a needle file and have had no further trouble in the subsequent 27,000 miles. Dunno how relevant this is to your situation but I thought it worth passing on the info and you can investigate and analyse accordingly. I assumed at the time that my bike had been fitted with a faulty pulley where the washer/flange had been fitted the wrong way round. Another forum member reported the same issues at the time, as I recall.

26-02-2020, 08:37 AM	#2
MotoNik Bronze Member Join Date: May 2003 Location: Sherbourne Bike: M600 Posts: 401	That sounds horrifying! Just received new tensioner pinch bolts, wavy washers, and e-clips for the tensioner bearings, so the new belts can go in tonight. Very excited!