138cc mega cam

P.C.

P.C.

Active Member
has anyone run a mega cam in a lifan?today i ordered a bci mega cam,hd valve springs and a copper head gasket for the orange lifan 138.i may clean up the intake port slightly.on a flat road with no wind it goes 62mph.i will update any top speed gain after the swap.
 
P.C.

P.C.

Active Member
thanks Fat, i do have an assortment of mains,i went from a 95 to a 97.5 so far.the motor has 2k miles on it.
 
6

69ST

Well-Known Member
That's a good mileage total for performance upgrades. The motor ought to be fully broken-in and if something was defective it's reasonable to expect that it would have shown up long ago, so no worries about thrashing it. No arguments with what Jared told you, optimal jetting will probably take some testing. However, there can be surprises. If the motor was cam-limited, the jet size increase may be less than intuition would tell you. I still recommend finding the rich limit, beyond which the motor won't rev-out cleanly at WOT. Do that & get the idle reset correctly and the carb should be as close to perfect as possible.
 
P.C.

P.C.

Active Member
i was surprised when i only had to go 1 up from stock.the plug looked too white when it was new.so now i figure maybe the 100 main when the cam is in.it was too much for it at the moment,winter temps may be a different story.i started the rejet when it hit 65 degrees.thanks guys
 
P.C.

P.C.

Active Member
ok the cam is in.i had a buddy port the head, ran it today for a short run,it pulls harder now.i can rev it up more.thats always a good thing! i stretched 3rd gear out to 48mph shifted to 4th and backed off.i didnt get a wot run in yet.the carb needs to be adjusted now.a plug chop is in order.
 
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