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Clunking Engine

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i was riding my bike today and i noticed my bike was making a clunking sound when it was put under strain going up a climb when it clunks the engine runs fine and does not lose power but the sound p****s me off and it makes me scared to ride my bike again incase it breaks it

Is this a "clunk" or a "rattle" sound, kind of like a bag of marbles?

  • Author

a klunk not a loud one just so you can here it when riding

This might sound daft but check that your swing arm bearings/dog bones arn't loose and that your sprockets aren't loose...

Paul Mac

Paulmac - Betas don't have 'dog bone' linkages as far as I know, however, the swingarm bearings or rear wheel bearings are suspect as are the headstock bearings.

I also think JTT is also on the right track - questioning toward detonation caused by low-grade fuel.

Did the knock just start, or have you started noticing it more and more lately?

  • Author

i have checked the suspension linkages and the ones at the bottom of the shock has a bit of play i dont think this is the problem it sounds like it is coming from the engine

someone told me that my big end was on the way out

I had a similar noise once only it turned out to be something really silly. I had broken the headlight off inside the plastic bracket and every time I went a bit faster it would bang against the steering head making an extremely strange knocking sound. It took me ages to find the problem as it only happened when I was going faster. It never occured to me to look at the headlight..... :rolleyes:

If you are sure that the sound is coming from the engine I would look under the clutch basket at the gear with the dampening assembly. I have seen the rivets loosen up and cause the cover to push-off a bit under hard pressure. makes a heavy clunking sound.

A bad burn could do it.

Bad (or old) gas.

Bad plug.

Air leak.

Dirt in carb.

See if a little choke makes it go away.

You can put a small ziptie on the shaft to keep it open just a little.

Does this clunck sound/feel like it is coming from the top end or the bottom, front or rear of the engine? Have you had anything disassembled lately. Check everything for tightness, before drawing any conclusions.

  • Author

my dad has had the whole clutch dismateled but i cant tell where the sound is coming from in the engine if it even is the engine making the sound

to charlies post i have found big as cracks in the manifold coming from the airbox to the carb im not sure if the cracks go all the way through it definitly aint the inlet manifold cause i only replaced it last month

  • Author

it only happens on hills and climbs when they get steep and the revs drop because the bike is strugling cause i think i have got it in the wrong gear

  • 5 months later...
  • Author

i finally found the problem it was the wrong plug i must have spent atleast 60 quid on plugs trying to find the problem i must of tryed every plug from heatrange 8 to 5 i was getting close with a number 5 plug that cured my plug fouling for good then i went for a 5 with a projected tip and a resitor and atlast i went for the 5 with just the projected tip i dont know how not having a resistor cured it but it has gladly it has taken ages to cure it

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