My engine (e5 with 24,000 miles) has developed a loose rattle at 2500 to 3500 revs only on a slack throttle. It is an engine speed noise and not heavy more a slappy rattle like a chain.
Any ideas?
Initial thought would be camchain tensioner sticking - had a BMW R80 in the workshop that was slappy, but that was high miles and adjustment had run out.
It’s quiet on tickover and beyond 3500rpm? All gears? Any rough running?
Hi Jeff
It is quiet on tickover seems quiet at higher revs as well but then there is more noise.
In all gears it is the same. The noise comes and goes but there is no roughness.
The noise seems to resonate at some revs (like a slack drive chain) which is why i think i agree with you - it think that either the tensioner has failed or it is not bolted in tightly.
Pity i was hoping for any other idea but it does not look like a big job
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The BMW was high miles, so that had actually stretched the chain/worn the sprocket, so hopefully that’s not your issue, perhaps just sticking? Various Japanese bikes had issues with that in the past, relatively easy fix, although I’ll confess to not knowing if it’s an known with the V85.
Just had a look at the layout Managed to get all 12 of the timing cover screws out but the timing cover is well recessed inside the frame tubes so i cannot give it a clean blow from opposite sides also with the alternator wires and the breather holding the cover am not sure there is clearance to remove the timing cover in situ… without dis-assembling the tank and area above the engine…
It has moved on a bit from the V50iii 
It doesn’t appear to be a common problem -has anyone here done this?
If the engine feels like it still pulls ok, check for loose stuff. The exhaust guard things come loose and make a racket. Good luck.
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silly question but… are you sure it is from the engine, the heat shields can come loose and make a rattle, which only happens are certain rpm
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As i thought it sounded too loose to be the engine I have tried thumping every thing in sight first with my hand and then with a dead blow hammer. Then I rode at the correct speed over about 300yards of cobbles and that did not cause the clatter.
Tomorrow i am going to go somewhere empty of people and try rolling the revs between 3500 and 2500rpm with the bike on the stand both in neutral and 2nd gear to see if i can hear the clatter.
I also need to check the rear as the only other thing i have heard that sounds this loose is a failing uj
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i went to somewhere quiet to play around and try to be certain where the clatter came from. While riding, the v85tt was getting noisier and noisier, clattering and banging around 3000 rpm like a chain hitting a metal chainguard. When i got there i was expecting a broken casting and maybe oil leaks, but no.
I tried hitting anything that might be loose and, as usual, it was all tightly fastened no rattles or clunks. So I started it up in neutral on the centre stand and brought the revs up to around 3000. No rattling or banging. So I put the bike in gear and started it clunk-scrapety-crunch, clunk-scrapety-crunch etc etc not good at all
So that noise that sounded like it came from the front when i was riding was actually coming from the back!
It had become so loud that i felt the bike was not safe to ride so it is being brought back in a van and tomorrow i will start investigating whether it is shaft or bevel box.
oh dear, hope you get it sorted soon, bearing in mind the factory closes all of august, parts will need ordered this month!
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I have not even got the bike back yet to see what parts are toast. I am ok with using second hand drive shafts or bevel boxes as they are mostly very reliable and can be checked for play before use…
But as I have not worked out if i can lift the rear in a stable way like we did on GRiSOs. i fear summer/autumn 2026 may be written off for me for biking.