moderate knocking on engine.

niteblade · Post by **niteblade** » Sun Feb 20, 2011 2:52 am

helping a friend post his question.

"my nc35 bike was in idling mode and i over-rev it till red-line and there has been some knocking sound ever since and moderate vibrations felt on tank, so do anybody know what happen to my bike(pls let me know what is wrong)?"

any kind soul would like to help him point of potential problems?

Post by **superlite** » Sun Feb 20, 2011 4:25 am

This is a wind-up right

Sounds like a bent valve or two I reckon.

amaechizzle · Post by **amaechizzle** » Sun Feb 20, 2011 6:12 am

I would be doing a compression test asap!

Post by **thunderace** » Sun Feb 20, 2011 10:19 am

Doh!

trademe900 · Post by **trademe900** » Sun Feb 20, 2011 10:34 am

How did you over rev it, they have a limiter.

Did you downshift too many gears?

Post by **Neosophist** » Sun Feb 20, 2011 5:10 pm

People don't realise that when the bike is in neutral you shouldn't rev it past 10,000rpm.

There is no load on the engine and it can damage parts, it says this in the Honda Manual too somewhere.. race warmup procedure is 2-4ktpm, 5-8k and 8-10k rpm if i remember properly.

id do what has been said and check compressions to make sure valves are not bent, use a screwdriver or engine stethoscope to locate the source of the noise.. it could be something silly like loose bolts

Bill · Post by **Bill** » Fri Mar 11, 2011 6:49 pm

i did not realise this, makes sence really when you think about it, i never rev it anywere near than in neuatral anyway (why would you need to) but what about when its in gear but the clutch is pulled in? i dont do this either but just woundering?

cheers

Bill,

Post by **skinnydog0_0** » Fri Mar 11, 2011 8:23 pm

Neosophist wrote:People don't realise that when the bike is in neutral you shouldn't rev it past 10,000rpm.

There is no load on the engine and it can damage parts, it says this in the Honda Manual too somewhere.. race warmup procedure is 2-4ktpm, 5-8k and 8-10k rpm if i remember properly.

id do what has been said and check compressions to make sure valves are not bent, use a screwdriver or engine stethoscope to locate the source of the noise.. it could be something silly like loose bolts

Mr Honda says, when warming NO GOING OVER 10K
You might be lucky and just dislodged a shim, but the valves can bend quite easily. Can you check the the valves and shims?

moderate knocking on engine.

moderate knocking on engine.

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