Out of nowhere. This crazy loud whistle just starts out of nowhere. It sounds like its from the front of the bike. I checked the fuel cap and its not that. Its driving me absolutely mad.

Anyone have ideas ?

 

What are the conditions when you hear the whistle? Stopped, moving (speed?) idle, revving? Or is it coming from the KTM near you whistling at your bike? Ha ha.

Ride on
Brewster

 

Some yamaha scooters had that coming from the electronic speedo sensors, cure was lube it.

 

Most often a whistling is a vacuum leak. Check that the carb is properly seated and the carb boots are not leaking. One common test it to idle the bike, then with an unlit propane torch, move it around areas that might leak, if there's a vacuum leak, it will suck in the propane through the leak and the idle speed will increase.

It could also be something else that's like a whistling, but a little more 'mechanical', like the cam timing chain adjuster not keeping proper tension on the timing chain.

You can try a mechanic's stethoscope (or put your ear on the 'soft' end of a screwdriver, then put the driver tip on different parts of the engine) to determine where the sound is coming from, although this is more useful for 'mechanical' noises than whistling.

 

Mine makes a high-pitched whine (which may sound like a whistle) from the oil filter. Usually this happens with brand new filters or cold days. It is especially noticeable when decelerating while in gear.

 

There are several threads on a whistling sound coming from their bikes.

Kawasaki Forums - Search Results

 

If it's the same noise that many of us have experienced, it's come and gone for many of us over the years. It's been guessed at from all angles, but I don't think we ever came to an absolute conclusion. The speedo drive or cable was a good guess, but some of us who had the noise didn't even have an operational drive or cable...Trail Tech Vapor replacement. Disc rotor harmonics was a good guess, but a lot of experimenting debunked that one too. I'm not sure that everyone had the exact same noise, but most of them pretty much were from the descriptions. It happened with '06/'07 models and with '09 and later models...so the electronic or analog displays weren't the culprit. Mine showed up for about a year then went away and has never returned.