Rattly Engine

Hi I have a CB500s Y2K which generally runs well. However, there appears to be general rattles in the engine with an occasional tap. Before I start to strip the engine, which I dont have much time for unless I know exactly what the problem is, what could the problem be? Is it the timing? Is it the valve clearances etc etc? I have had the bike for nearly 2 years and it has always been rattly but it is getting worse, and with only 21,000 miles on the clock, and a previous owner who neglected the poor thing, I need to know what is wrong with it. Any comments would be great.

carb synching? easy job and dont cost anything if you can borrow gauges

Hello!

I am assuming this is mainly noticable at idle when in neutral.

Have you tried pulling the clutch in? If the noise goes away it is almost definatly the 'clutch basket rattle' which is very widespread in CB500s and, to the best of my knowledge, entirely harmless.

If it doesn't go away it could be caused by the camchain tensioner coming to the end of its life - when this happens it does not tension the camchain as well as it should and this can cause a rattley noise.

It could also be caused by the valve clearances being wrong, however these tend to 'tighten up' as they wear so their rattleing tends to get quieter rather than louder over time.

If you don't know when the valve clearances were last checked (and you don't mind taking the engine apart a little) it would be worth doing this *and* replacing the camchain tensioner, just to be on the safe side.

Hi mark,
If your bike has only done 21k, im pretty sure valve clearance or clutch rattle wouldnt be your problem. Because of the age of your CB i would check the camchain tensioner, they tend to loose there tension over age most of the time. Hence why your rattle is getting worse.

hope this helps

kwackboy wrote:Hi mark,
If your bike has only done 21k, im pretty sure valve clearance or clutch rattle wouldnt be your problem.......

My '96 bike (first of the Italians) has the clutch rattle at 8500 miles. My ST1100 does it and the Blackbird I had before did it. It's a Honda thing and nowt to worry about - they all do that, Sir.

Thanks for all your replies, I have found one rattle... It has been caused by a stretched after market chain with a dodgy link! At times the link hits the front sprocket and makes a weird noise! The rattle is still in the engine but new OEM chain is on the way from David Silver Spares. Will be working back from the worse noises to get to the quieter rattles but I reckon I still need to check the cam chain tensioner though but, of course that will have to wait for now as a new chain and sprockets cost a fortune, as has the new rear tyre. Two birds with one stone............

I'm glad you found the worst of your rattles: a knackered chain is a good thing to be rid of!