Lifan 125cc ticking.

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bmxreeves

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So i just did a top and bottom end rebuild (piston, rings crank, rod, bearings etc) and now all of a sudden I have a bad tick. Note that the head is fine, and off the original LIFAN 125.

So let me explain, My clutch got stuck engaged, rather than cracking the case open I got a bottom end off another motor and assembled. (there where no spare parts after).

Valves were adjusted to .003 (intake) and .005 for exhaust.

Timing is correct, runs and has tons of compression.

I even put a different head on, and the valves adjusted on that one aswell.

I can not for the life of me figure this out. Motor experts of the interwebs i need you!
 
When you rebuilt the engine, did you inspect the timing chain?, it could be possibly slapping around or simply worn out, that's all I can think of atm with the info you have given
Cheers
 
may or may not be but sometimes when you change your oil, it is alot smoother so the ticking is more obvious
 
When you rebuilt the engine, did you inspect the timing chain?, it could be possibly slapping around or simply worn out, that's all I can think of atm with the info you have given
Cheers

I did not have a good inspection on it. But it was not loose, at all. I can look into that. Thanks.
 
may or may not be but sometimes when you change your oil, it is alot smoother so the ticking is more obvious

Yes I agree, but. I ride this bike a lot, and hard. Oil gets changed every 2-3 rides depending on ride conditions and length.
 
So i checked the timing chain and all is good on that. Any other ideas?
 
Did you remove the timing chain? And then check how much of an arch you had, it might be unnoticeable with the chain under tension, worn chains have physical play between the rollers and peened pins, inspect your guides for gouges, also ensure there is still a rubber tip on the tensioner shaft that is located next to the drain bolt, it can also depict on what oil your using, or even how much you putting, if this is all correct, id be looking at bearings as the next place, of the source of sound,if you pull in the clutch does the ticking go away? If so it's clutch related,
 
Did you remove the timing chain? And then check how much of an arch you had, it might be unnoticeable with the chain under tension, worn chains have physical play between the rollers and peened pins, inspect your guides for gouges, also ensure there is still a rubber tip on the tensioner shaft that is located next to the drain bolt, it can also depict on what oil your using, or even how much you putting, if this is all correct, id be looking at bearings as the next place, of the source of sound,if you pull in the clutch does the ticking go away? If so it's clutch related,

It is not clutch related. It’s a consistent tick, which makes me the thinks valves. And I’m pretty sure it’s not bearings as the bottom end was running and smooth a couple months ago. I will look into the timing chain thing tonight. I’ll let you know if anything. Thanks.
 
When i would adjust the valves on my old lifan 125cc (0.03" intake 0.04" exhaust). It would have alot more compression kicking it over and would make a ticking sound on idol. This is the tapets and is normal.
Hope this helps ya
 
Last edited:
SO. Been a minute since i’ve been on. Finally got to tearing into the ol girl and did seals, and looked at possible problems. So it’s not the timing chain as a fellow said up there. It’s not valves, this is making me think bottom end (bearings, rod etc). Suggestions on where to look?
 
Ticking sound on these engine is normal when valves are adjusted to the correct clearance. If its running fine/riding fine, then i wouldnt be too worried mate.
 
If possible could u upload a short video of it running to youtube and post the link here?
 

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