Scott8155 Posted February 25, 2015 Share Posted February 25, 2015 Alright chaps. So riding home from work my xt 125 2010 suddenly starts a loud knocking coming from the bottom end of the engine. It happens when the bike is moving past 15 mph, not when idling. Ideas ? I'm not a mechanic but I'm eager to split the engine and have a look and I've learnt slowly but surely. Would it be cheaper to buy a new bottom end or the parts depending on what it is? Link to comment Share on other sites More sharing options...
Moderator drewpy Posted February 25, 2015 Moderator Share Posted February 25, 2015 does it depend on revs or road speed. ride with the clutch in over 15 mph and see if it still knocks Link to comment Share on other sites More sharing options...
Scott8155 Posted February 25, 2015 Author Share Posted February 25, 2015 Pretty sure it's speed drewpy but I will double check Link to comment Share on other sites More sharing options...
Moderator Airhead Posted February 25, 2015 Moderator Share Posted February 25, 2015 could be a stiff link in your chain, see if the chain links have any kinks when between the sprockets ?Can be quite commonplace if you ignore your chain oiling in winter !You'll hear it when the engine is under load...and it'll be hard to hear with the throttle closed Link to comment Share on other sites More sharing options...
Scott8155 Posted February 25, 2015 Author Share Posted February 25, 2015 Yeah I thought of that airhead, thanks though. I do keep on top of my chain maintenance. It definitely is coming from the bottom end and is a really loud knock Link to comment Share on other sites More sharing options...
blackhat250 Posted February 25, 2015 Share Posted February 25, 2015 When the engines at idle , and you rev it , is noise still there ,? Link to comment Share on other sites More sharing options...
Scott8155 Posted February 25, 2015 Author Share Posted February 25, 2015 No it isn't blackhat, only when moving Link to comment Share on other sites More sharing options...
neversaydie Posted February 26, 2015 Share Posted February 26, 2015 Yeah I thought of that airhead, thanks though. I do keep on top of my chain maintenance. It definitely is coming from the bottom end and is a really loud knock Double check the chain and sprockets, remove the front sprocket cover and check inside it, spin the rear wheel by hand while watching the front sprocket to see if the chain jumps or theres a stiff link, you may not see it at the rear spkt due to the larger radius Link to comment Share on other sites More sharing options...
KevtheRev Posted February 26, 2015 Share Posted February 26, 2015 Can you feel the knock through the footpegs ? 1 Link to comment Share on other sites More sharing options...
blackhat250 Posted February 26, 2015 Share Posted February 26, 2015 At least we know its not the engine , as kev says thru the footpegs, = sprockets or chain, My tiger did this on over-run last year, it turned out front sprocket was hooked teeth,, Link to comment Share on other sites More sharing options...
motherof2 Posted February 26, 2015 Share Posted February 26, 2015 Hi there how do I start a new topic Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
KevtheRev Posted February 26, 2015 Share Posted February 26, 2015 I was trying to rule out big end or main bearing trouble Blackhat , 1 Link to comment Share on other sites More sharing options...
Moderator drewpy Posted February 26, 2015 Moderator Share Posted February 26, 2015 I was trying to rule out big end or main bearing trouble Blackhat , It can't be the engine, its transmission related Link to comment Share on other sites More sharing options...
blackhat250 Posted February 26, 2015 Share Posted February 26, 2015 [ Quote kevthe rev , rule out big end ] So was I kev " Link to comment Share on other sites More sharing options...
Scott8155 Posted March 2, 2015 Author Share Posted March 2, 2015 Sorry chaps I've been a busy bee. There's no stiff links in the chain, I know by only saying knocking you can't imagine my problem clearly but the noise is certainly coming from the bottom end of the engine, not the front sprocket/chain. I can't really feel it at the foot pegs but it's more of a loud slap and I don't think the vibrations would be strong enough to feel if that makes sense. Link to comment Share on other sites More sharing options...
blackhat250 Posted March 2, 2015 Share Posted March 2, 2015 if you pull the clutch in does it quieten ,? 1 Link to comment Share on other sites More sharing options...
Scott8155 Posted March 4, 2015 Author Share Posted March 4, 2015 No it doesn't blackhat, the noise kicks in at around 15mph, at first it was 25mph, and stops again when the bike slows down past 15mph Link to comment Share on other sites More sharing options...
Moderator drewpy Posted March 4, 2015 Moderator Share Posted March 4, 2015 so if it doesn't knock at standstill,with the engine running, its not the big ends!! As per my post #13 Link to comment Share on other sites More sharing options...
Simon46 Posted March 4, 2015 Share Posted March 4, 2015 Mains umder load? Link to comment Share on other sites More sharing options...
blackhat250 Posted March 4, 2015 Share Posted March 4, 2015 Balancer shaft " Link to comment Share on other sites More sharing options...
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