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Quick question.
Should I be hearing this belt whirring/rubbing type noise when running? The bike has done 30k, and I am not very technical, but willing to try under supervision. As this is my first boxer engine I don't know what is normal/not normal.

You will get some noise from the belt and also the alternator unusual noise for a bike but these are unusual bikes

Ok, that is really good to know, was worrying that a bearing was going or something.

It all depends how noisy it is if you have an hour to spare it could be worth taking off the front cover [four caphead bolts] and have a look at the belt if it looks good and is not over tight or lose start bike give belt a spray of wd or simular it should quieten right down [the noise will come back but you will know that it's only the normal belt noise if it's still noisy after spraying it may be the alternator front bearing [these go more often than the back ones due to being more exposed and having the belt tension on them] try soaking the front of the alternator behind pully with your trusty can of magic when the spray gets to the bearing it will quieten down if it's shot

To me it sounds like normal belt noise

Hope this helps Dai

That's great, I will have a go at the weekend. Thx Dai.

To be a bit pedantic, Im not keen on putting WD40 on belts. It stops the squeek, but will eventually promote more slip.
IMO its far better to stop the noise with the correct tension, or failing that use a squib of belt dressing. As Dai says take the cover off and listen, you'll soon work out if the noise is a problem and where its coming from.

Mick

Only spray the belt to see if it's the belt or something else making the noise as i said i don't think it's anything to worry about and a quick squirt of wd will set your mind at rest the alternator will make some noise but shouldnt be noisy and when you get the cover off check the condition of the belt

As a rule i would say it's not a good idea to spray any belt with wd unless it's for fault finding

Don't worry about the belt slipping it has to be fairly tight if you can twist the belt 90degrees it's about right, nearer 180 it's too lose.

Since the vee-belt runs inside a ventilated casing, it can pick up rubbish...in my area there are a lot of small flints, and by the time a belt change is due it has become more noisy (a ticky-ticky noise) as the small pieces of stone have worked their way though the belt to rub on the pulley faces.

Bigger stones caught in there will shred the belt quickly.

Suggest whiz off the plastic cover (only 4 small screws) to have a close look for incorrect tension; and whilst there clean any debris from the belt grooved face. I'd rather try this small task first, to know that the belt is OK before taking on the the dismantling work to reach the alternator!

Many Trixters have found belts that have started to disintegrate, and I can tell you these engines run only a few miles once the belt gives out, as the battery is quickly drained - and then you are usually stuffed!

WD40 is essentially parafin, it may damage synthetic rubber. If there is a chuffing noise, it suggests a fray on the belt slapping regularly against something more solid, indicative that the belt is about to fail. This is also the sound you get from a cam belt just before it goes. Popularly heard on Renaults. NB 30k on a ten year old bike, it probably wants a new belt. Cut the old one off and wind the replacement on starting from the smaller pulley.

I have ordered a new belt today £13, better to be safe, and change it whilst the cover is off.