First, the bike is a 2009 KLX250SF, Don't even have 300 miles on the bike yet however I think I hear a knocking noise in the engine. I've tried to research this out but I've come to realize I'm going to have to get some input. FYI I just want a good idea of the issue before I head to the dealer.

What is happening is when the engine starts to reach ~5500+ RPM during acceleration after I hit 3rd or 4th gear I hear what I believe is a knocking noise from the cylinder. Now seeing as its break-in period I try not to run the engine beyond 4000 RPM anymore then I must, but either way it's there. It doesn't happen when not in gear or in lower gears.

I'm wondering if I'm being paranoid or if it's a legit issue, it's been a long time since I was on a bike and I can't claim I would know exactly what to listen for, but it deffinently sounds abnormal.

any ideas before I head to the dealer?

 

so, a good chance of detonation while under a loaded condition. Up the octane and try that. What is the bike?

edit- I see your edit now and it seems like your ride would be lugging away in 3rd gear at 4k rpm. But we will need to hear from the klx guru's.

 

I suppose I can try a different brand, already running premium (93) here in NC. But it's been from the same station.

 

I am going to copy this thread and post it up in the klx section since there have been no guru's noticing this thread yet.

 

sounds like you might be experiencing some detonation. Almost 300 miles ? That engine was broken in 280 miles ago. change the oil and give it some revs.

 

It's your cam chain and the fix is a guy on this forum named Mark Kreiger as he has a manual adjuster that will solve your issue and make your bike quiet again.

 

Yep, without hearing it in person, this would be my first guess. The cam chain noise pops up quite a bit.

 

That would be my guess, too. And, don't waste your money buying high Octane. This is NOT a high-performance, high-compression engine. You gain NOTHING by running high octane fuel in it, and, depending upon what is being use to boost the Octane rating, you could actually be increasing deposit formation in your combustion chamber. Google Octane and read up on it if you have doubts.

Hope you find the source of the knock and it's an easy fix (Krieger Manual Cam Chain tensioner...hint, hint )

 

Also I really dought Kawasaki would be much help in solving this issue as it is a common failure of a stock piece that is more than common on these bikes. As the fix for them would be to first admit the the (stock) bike has issues. I know when I went back to my dealer they were of no help and couldn't seem to hear that garbage disposal noise that occured between 5 and 6 k.

 

What does your spark plug tell you?

(Some fortune tellers use Tarot cards. I use spark plugs....)