Hi. I have some sort of rattle during engine braking, when I'm changing down the gears to approach a junction. I thought it might be the chain, but the chain is at the correct tension, as indicated by the 'window' in the chain guard. Bike has 8k miles only. Can anyone suggest what the problem might be?

Hi LR, I would check the cam chain tension adjuster.

...Paul

Hi. I have some sort of rattle during engine braking, when I'm changing down the gears to approach a junction. I thought it might be the chain, but the chain is at the correct tension, as indicated by the 'window' in the chain guard. Bike has 8k miles only. Can anyone suggest what the problem might be?

Hi Bob,

I would guess Paul is perhaps on the right track but a loose cam chain on an SR125 would also give a rattle from the engine at idle (do you suffer from that ?) Another point to look at is if the engine is loose in the frame, this would cause the drive chain to rattle against the chain guard & also give the correct chain tension when the bike is stationary. another thing to check is if the (naff) chain guard is not warped as on 'over run' the chain will flap about and perhaps hit the chain guard !

Regards Jim