Hello there - I realise this is an old thread but I just want to ask, did the whirring noise come back?

I have a similar noise on my klx and it's definitely not the camchain tensioner.

Colin

 

My chain is noisy but that’s expected. It comes from the front sprocket area.

 

If it does it when sitting still, hold the rpm at a range where it is made and listen around the engine to try to locate the noise. If it is only making noise when rolling look at the drive line.

 

It's from the camshafts area and more towards the intake camshaft. The only thing i can see, is the timing chain guide (intake side) touches the inside of the cyl head on the right side. I am wondering if the noise of the chain, rubbing against the guide, is being transmiited to the cyl head and the cyl head is acting like a 'sounding board'

 

Why are you so certain it isn't the tensioner? After all, it is in the back of the cylinder head on the right side. Does the bike have the OEM tensioner? If it does and you live in the U.S. about the least invasive and least expensive thing to try is the cam chain tensioner. If you have a manual tensioner you may want to see if it is too tight. If you have the manual tensioner this link should take you to a tensioner instruction sheet. click here If the link doesn't work let me know.

 

Manual tensioner or original auto tensioner, the noise is the same. I have had KLX250's for 12 years now and worked / serviced many others but never experienced a noise like this.It's not a worrying noise but it certainly gets on my nerves . Next step, modify the rear cam chain guide so it doesn't touch the cyl head. I'll update later.

 

That is exactly what should happen. Better slightly loose than too tight and creeping in is a good method. The reason why I use "finger tight" is because it is near impossible to exert enough torque with your fingers and thumb to even reach a couple inch-lb or a Nm so it can't be overtightened. The one problem with trying to adjust on the KLX250 is the exhaust location. On my 650 I can get the bike up to operating temp, then adjust in until the clicking disappears, usually I back out again slightly until the ticking returns then slowly adjust in. That way I know I am exactly where I want it to be. But the initial cold set using finger tight works well too. I use a wrench on the bolt on the 650 only because the bolt is hot, the bolt is never tight enough to feel resistance on the wrench. It is also the reason why I work through the ticking twice, backing out to hear the click. The bolt movement is virtually never even a half turn in doing the adjustment work.

 

Wish I could be there and help. Not that I know the problem or solution, but that I'd like to know what the issue is and what you have to do to resolve it. Please let us know.

 

Touch the cylinder head ????? You need some help.

 

Hi Guys,

Thanks for your comments.

I'll try and upload some photos because what I'm trying to describe is is difficult. I'll try and upload a video too.