Hi all, I'm having so much fun with my new klx250 but there is a new noise that seems to be becoming more apparent. Here's the full description, maybe someone canhelpme findthe source ofthis.

At significant speeds (above 30km/h) a constant pitched whine, sounding like a whistle, can be heard. At high speed, the wind engine noise makes it pretty much inaudible, but it is noticed when slowing down, the constant pitched whine becomes obvious. As you slow down to a stop, below 5km/h it stops. Now today, I tried to diagnose it better.
I was slowing down on a quiet road and heard it all the way down to low revs in 1st gear. Clutching in, putting it in neutral makes no difference, it depends only on the wheels turning.
I actually jumped off the bike in neutral and running along side it trying to identify the source. I can only suspect it's coming from the engine area, I don't think it's the hubs or discs. Braking hard front or rear doesn't make a difference. Also, at this threshold of speed where it stops, it sometimes goes intermittent (whine-whine-whine...) and almost seemed to be the frequency of a wheel rotation.

I had a guy at the shop where I bought it take it for a spin and he heard it. He doesn't know either and says don't worry and hope it goes away, if it gets worse, bring it in. Coming home tonight when approaching a stop, I was becoming self conscious that pedestrians can here this.

That's about it.
Thanks!

 

I'll tell you exactly where it's coming from if you're talking about an '09 model. It's the tip of the upper radiator shrouds vibrating against the metal tank where they curve and go inside the seat/tank area. They just sit against the tank at that point with nothing to hold that area firmly. They should've stuck a tiny strip of rubber between that edge of the plastic shroud and the tank. This is something I plan to do. It's annoying but I guarantee that's it. I heard it on my first ride and wondered how long it would be until someone asked about it. Just put your hand on it and it disappears.

 

Does this noise only happen when riding on the road surface or on dirt also?

If the noise only appears on the road surface it will be the tyres ( tires ) whining on the tarmac.
Nobby tyres on the road can generate a whining noise

 

If you have a jack, put the bike up and spin the tires by hand. Could be your speedometer drive needs to be greased.

 

nah, it's just what I said. Trust me, I hear it everytime I ride my new '09. My post explains the problem in detail. Unless you have seen an '09 and how the shroud ends just sit against the tank under the seat or have ridden one you just don't know what sound he's trying to explain. It's not the tires, they're quiet and the speedo pickup is not the same as the old bikes.

 

Mine is the '09. I've noticed a buzz vibration sound sometimes coming from the plastic around the tank, I just squeeze it with my knees and it stops. I'm not too concerned with this. If this is what you're describing, it's different from the high pitched whine/whistle I hear coming from the engine area. I'll try to diagnose more on my next outing.

 

yup, vibrating plastic against the tank. Mine did that too... before it had to go back to the shop!