jailing motor?

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1 x 140cc motor
run in motor + 40min at black duck =
]


NICE !!:D :D

Lifan got his probs with unbalanced flywheels lately....:eek: ...here we got two engines too !!...its kind of having luck to get one with a balanced one:p
 
I just checked cams from Lifan 120, 125 and 140 cam. They are running NTN and FJK japan bearings...
That is a bit of nasty business with that crank!
 
I don't know that the flywheel balancing is sus. They look to be drilled quite carefully and no two are alike, and logic tells you they have been balanced in a computerised balancer. My best guesses would be the cast cranks not being checked for cracks or flaws in production. A bad one comes through occasionally. Also a step or score in the crank can create a failure point. The 124 crank looks like it snapped right on the step down. At the rpms we spin these cast cranks and abusive treatment we give them, its a wonder more don't fail.
 
How many 55.5 or 59mm Lifan cranks have busted on you Mack ?????
 
ntn fag and skf bearings up to 30mm i.d are made in tiawan weather printed or not i know this as my sister company is the direct importer of ntn

as for the crank i'm not sure if its a visable issue but more a casting issue
if you look at where my mates snapped you can see what looks to be air bubbles in the steel

but hey i reckon we are near done with this one good stuff
 

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