Very loud knocking noise....

[ChowderV4]

i know this isnt going to be nice but i need to find out possible causes.
my nc30 has developed a rather loud and worrying knocking sound which i have pinpointed to be coming from the front cylinders.

how terminal am i expecting......

[Drunkn Munky]

Kaboooooooooooooom!!!

Sorry that wasnt very helpfull was it, doesnt sound good tho

[alexwitham]

The above made me laugh to the point of snorting.

[ChowderV4]

haha , pretty much what i was thinking......
turrrrrrrd!

[Drunkn Munky]

You could always cane it round to 14k in neutral a few times, if it throws its toys out the pram you know it was on its way out, if it doesnt you've most likely just fucked it anyway. More great advice

Has it done big miles?

oh and wheelies, not good for the front cylinders are they???

[Hadies]

Check that the exhaust hasn't come loose at the front. Happened to me last week.

[Neosophist]

Erm, don't EVER rev the bike over 10,000rpm in neutral.

It's written quite clearly in the Honda book, it's the easiest way to break something fast.

The engine doesn't have any load on it so parts explode.

Knocking noise doesn't sound good.. high up or low down?

Could be big end-bearings / top end valves. How's it running?

[mick.mh2racing]

I'm thinking something simple like exhaust a bit loose or something serious like shell/crank bearings.

[ChowderV4]

Defiately not exhaust, it's top end front cylinders. Bikes got about 36k oil and filter every 4k and I don't wheelie it. It was running fine prior but now when I rode it last the noise was very loud and it was down on power.

[skinnydog0_0]

could be a shim missing, causing a knocking sound. Best to get the front head off and check all shims are in place and that the cams are in good order.