NS125R werrring noise at front starting from around 6000rpm

richard123456... · L Plate Warrior Joined: 22 Dec 2009 Karma :

Hi,

I wonder if anyone can help me? I actually have an NS125R not an NSR but I guess this would be the best place to ask my question.

It's been fairly cold where I live recently (in Leeds) and sometimes my bike has started to make this strange high pitched noise after I hit 6000rpm which stays the same until the revs drop to below 2000rpm. It doesn't get less bit by bit, it literally just drops away. I think it sounds electrical as opposed to a scraping or scratching noise. It's similar to the noise that a screen wash pump makes on an old car when its empty...that's probably the best way I can describe it.

If I drive slowly and never put the revs up too high, then I can go a whole journey without hearing it, but if the noise does start it will keep making it until I slow right down or come to a stop. Then it won't start again until I hit the higher revs. It's really weird. Like I say, this has only started happening recently - could it be linked to the cold temperature or is this something to do with a part such as the alternator that needs replacing?

The noise is definitely coming from the front of the bike either under the gauges or under the petrol tank. The bike has a new battery which was purchased in May and was last fully serviced by a garage in September.

Any help anyone can give would be greatly appreciated.

Cheers,

Rich

buddy · Trackday Trickster Joined: 07 Mar 2009 Karma :

yeah i had a similar thing but it was at like 8000 if i was thrashing it and gradually let the revs drop back past 8000 rpm, just a really high pitched noise, just like what you described

sorry this isnt much help as i havent found out what it is lol and i cant take the revs that high as im running it in as i rebuilt it recently.
____________________
When this baby hits 88 miles per hour... you're gonna see some serious shit.

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Is it at all road speed related? Can you trigger it while not moving?

If it is rpm related and behind the clocks then I would suggest checking the rev counter and cable first (may as well check the simple and obvious first). However not much else I can think of that is rpm related in that area.

All the ebst

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

redline · Derestricted Danger Joined: 12 Jun 2009 Karma :

I had this type of thing happen on a KMX, In my case the noise was coming from the left engine casing. It turned out to be a part of the (cheap) gasket, which was slightly torn, being flicked by the flywheel when revved above 7,000 revs. I don't know why it did it at 7,000, but not below, unless it was only triggered at that specific velocity.

When the casing and gasket were off the engine, it revved much higher than 7,000 without the sound. Trimmed the gasket and replaced it. The noise stopped.
This might not help you, but it might be something equally random.