Loud pop/crack/bang from lifan 125

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there is a spring loaded tensioner behind the stator, i'm not 100% sure if it is oil pressure fed though.
if it is then thats ok.

did you set it at tdc when put the cam gear/chain back on?
cam marking at 9 o'clock, flywheel T at 12 o'clock ?
 
Yea I did, still won't start.. But sounds back to normal with the valves. I don't see why it won't start.. Sounds like normal but just dosnt start
 
did you set the valve clearances?
have you checked for spark?

spray a bit of fuel in the carby and kick it over
if it starts and dies or want's to start then it's a carby problem
 
Il pull carb apart tomorow and make sure everything's okay, I checked for spark before input helicoil in so it should have spark. Helicoil worked perfect after I cut it to lenght, only did the exhaust clearence because I loosened the rod a bit.. I thought other one would be okay, but I will cheak it
 
Carb is okay, and all in spec, clean ect. But still won't start :/ new spark plug, still nothing. Havnt checked the inlet valve cleance yet, I don't see why it wouldn't be the same as when I toolkit out? I did the bottom one because i fiddled within before I took it out
 
Defently has spark and fule. Still not starting :/ could it be the helicoil not letting the spark plug spark? Sounds good though, like it will go good when it dose fire up. Just sounds like normal but won't start..
 
yeah but remember the old inlet valve bent for some reason !!
hope it wasn't because the clearances were done wrong ?

the Helicoil wont stop it from starting,
but i'd think you'd probably be loosing a little compression seeing that the Helicoil is the wrong thread pitch.


so when you kit it over a couple of times quickly pull the plug out and check it is wet.
 
It's wet, that means its getting fuel right?
Would have been the exhausts' clearance that was to tight to bend that valve I reckon.
i got all those shavings out, and when i looked at the cam shaft bearings they were perfect :)

It's seemed to turn the spark plug thread to the same pitch, it goes in nice and solid anyway


Would having the inlet clearance set wrong, make it hard to start or not start ?
 
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yeah, if the clearance is too small it will make it harder to start (eg smaller than .004" / .1mm)
but would have to be a fair way out
 
It did make the kickstarter "stop" at the same spot as m bros bikes witch runs, and it was a fair bit off. When I kick my bros engine over (same engine) With killswitch off, can oly hear air Cingular from the muffler, on mine. I can hear both muffler and air filter "air noises" dose that indicate a problem ?
 
when you set the valve clearance it was on tdc then, both markings crank to case, and cam gear to head both perfectly lined up?

you should hear it suck a bit of air into the carby, then you'll hear the exhaust

and we still can't see any pics, so if there was something obvious someone might notice it and we could help you out.
 
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Yea evrything is fine, that's what has e stumped..if it was somthing obvious i would have found it by now :) i wil take a few and upload them using k brotherspone as minis cracked and it's hard to work with( wh I never post pics)
 
The gasket I made isn't the best, and the one for the cam cover has a split in it. But that hasn't stoped engines runing for me before si figured it would be fine just to start it
 
How do. Tighten the cam chain up? Seems like its the problem, started up nice with chocke but had to old throttle to keep it goin and had to let it die cuz I was scaring the horses haha couldn't get it t go again.. But I dropped the oil and re did the timing it was slightly off, it started after i put a new flywheel on, the by that holds it to the crack got a it worn and was kind of loose.. Im sure after I get this cam chan tight and re do cave clearences just to make sure, it sound run. Just don't know how to tighten cam chain, I know where the tensioner is, but is it adjustablein any way? Or dose it just hold tension on it/ release tension
 
Lifan 125 cam chain is loose and slaps engine cast/timing problem?

Hi guys, my lifan 125 wouldn't start, the spark plug hole was threaded so I fied it with a helicoil but while doin that I noticed the exhaust valve was bent, so I changed it for a straight one ( not new ) and after putting it all back together to test start, it won't start, flywheel felt a little loose so I replaced it and it did start for a bit but I killed it soi wouldn't scare the horses. But couldn't starting again.. So I took the flywheel cover of my brothers bike and had a feel of the flywheel and it felt like mine used to, my flywheel feels like it has a " soft spot" where the chain gose loose and after dropping the oil and demoing cam cover I could see it coming loose at the bottom of the cam sprocket every revelotin or two the flywheel made.. Dose the can chain need to be replaced? Or can't tighten it using the cam chain tensioner? As far as I know, the cam chain tensioner just holds tension on it (to run) then lets you release tension to remove parts, ect ? Bit lost. Any helps much appreciated
 
Yea it's still on there, every reveloution the crank makes it pushes down on that rod /loosning cam chain
 
It's taunt at TDC but there is a soft spot. And the tension rod gets pushed down on the spring ? When it dose that, the cam chain gose loose at the bottom of the cam sprocket. I spose I need a new cam chain? I tried a longer spring out of a ducar 125 but just made it to tight and still gose loose :/ sounds awfully squeeky in the front end too. What would that mean
 
so why are you so worried about this cam chain?
once the engine is running the oil pump pumps the engine oil through that tube and puts more pressure on the tensioner.
are the ports in the tensioner tube still open and not blocked up with old oil?



put up a picture of your original cam chain
sit it like this and show how much it can bend sideways, don't force it
the top chain is ok still, the bottom chain is worn out/stretched (these are YX/ZS Cam chains by the way, so look slightly different to yours, the Lifan cam chain will look like a mini version of the drive chain for your sprockets)

 
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