Over the last couple of rides the motor on my KFX400 has developed a very loud knocking sound from the right side of engine.
Thought it might be the valves at first because it wasn't too loud, but I checked em and they are within spec.
Listened close to motor and the sound seems to be coming from lower down behind the oil filter I think. Have not checked the cam chain tensioner yet.
Any other thoughts besides taking it in to the stealer?[img]i/expressions/face-icon-small-confused.gif[/img]

 

I'm guessing cam chain. Suzuki uses poor quality cam chains. All of their bikes seem to do it including 2 family friends' Vinsons, and my Eiger.

 

Thanks for the reply, but I went ahead and tore down the top end today and figured out the problem. Piston is toast, but i may be able to salvage the cylinder.
OIL STARVATION!!
A week ago, my nephew was runnin' around shootin' off his full auto AIRSOFT gun (the ones that shoot the little plastic BBs). The BBs were flyin' around and ricocheting everywhere. One of them mus have gotten stuck to the funnel I used to do an oil change the next day!
I knew there was plenty of oil in the quad, the trouble was very little was getting to the motor from the reservoir, due to that stupid little BB I found stuck in the supply line! F*#k!@$$.
Thing is I'm pretty careful with the cleanliness of my funnels (and tools). Wiped it off good before using it, but must not have seen that little bugger in there.
[img]i/expressions/face-icon-small-disgusted.gif[/img][img]i/expressions/face-icon-small-blush.gif[/img]

 

Oh man that F*cking sucks man i would be p*ssed. Hope all goes well for you!

 

Yeah..dealer listened to it and said it was the cam chain too.

Nephew is only 7yrs old, so his allowance won't cover it for quite a while. Think I'll just loosen the axle on his BMX.

Kidding[img]i/expressions/face-icon-small-wink.gif[/img]

 

Get your nephew in there with you thru the whole project. Cleaning parts and tools along with seeing how much money it takes to correct this problem may teach him something. At least he will see how an engine works.