Engine Noise (Knocking)

[probro529]

Hello Everyone,

So this is my first time posting and im still new to this page, so bear with me.

I own a 2006 Suzuki GS500F and ive had for almost 2 years now.

It was until recently that i notice my bike made this sort of knocking noise, i did lurk the other threads and its not a consistent knocking. It only happens when im in neutral and i raise the RPM to about 2500 revs. It flutters and sits there a bit, then the knocking noise comes in, but its just a single knock and the revs drop back down to 1500. i can repeat this and it happens every time.

Any idea or solution means a lot

thanks 

[prmas]

That is probably a lean missfire. Check for vacuum leaks or unbalanced carbies. There are other threads to explain how to do both of these actions. If it idles OK when hot it is most likely unbalanced carbies because if the idle jets were blocked or you had a vacuum leak you would have stalling problems as well. As we all know, these engines run very lean and retarded so occassional backfires or missfires are to be expected.

Mine is a K9 and has always done it to a slight degree at the same  (2500) revs, especially during warm-up, but it is not really a problem so I have not bothered to do anything about it. USUALLY, at N.O.T, it does not do it at all. 

That reminds me, I must do the ignition advance "mod" now that it is out of warranty.

Macka

[probro529]

Sweet, thanks prmas. Yea mine does the exact same at idle. And after it has warmed up it doesnt happen, but otherwise its fine.

What do you mean by k9? is that the chassis line? What is the advance ignition mod?

I'm also looking to do a few small mods on the bike

[prmas]

K9 is the year model. It was built in December 2008 for 2009 sale. I bought it new in Feb 2011 straight off the showroom floor. So technically it was just over 2 years old when I bought it new. It still looks brand new now with 19,oookm on it. It has only been ridden in the rain twice and was washed and dried straight after. It is my baby.

As for the ignition "mod": there used to be a different rotor available for the crank sensor which advanced the timing about 4 or 5 degrees. I believe that it has not been available for at least a couple of years. The same effect can be gained by slotting the holes on the sensor's mounting plate and rotating it slightly counter-clockwise. There is a thread on that subject explaining how to do it. 

Macka