jailing motor?

[themountain]

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

NICE !!

Lifan got his probs with unbalanced flywheels lately.... ...here we got two engines too !!...its kind of having luck to get one with a balanced one

 

[Mack]

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!

 

[Mack]

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.

 

[Cactus Jack]

How many 55.5 or 59mm Lifan cranks have busted on you Mack ?????

 

[coolmodee01]

ntn *** 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