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Ok I want a big engine....but I've read about the weak transmissions in the 138cc's and don't know if I want an oil cooler. So which 125cc Lifan do I want?
125cc vs 138cc Lifan
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You want a lifan 120 or a gpx 125. Both have primary mounted clutches. The lifan is good b/c it already has a big valve head on it but it has a shorter stroke than the gpx. Both have their pros and cons of course. But, if you do a search you will see that either one is a good start.
Both have 4spd trannies and parts from each of them will swap out but to get the most out of either of them you need the big valve head and a big bore kit and bigger carb. You can get 12-13hp easily out of either of them but it will be cheaper to get it out of the lifan b/c it already has the head you need. Either way you go, you will need an updated shift star for the shift drum to clear up the false neutral problem. They tend to go to neutral when shifting from 3rd to 2nd b/c of a poorly designed star and weak detent spring.
And both can be started in gear if you crash and need to get going fast. The crank mounted manual clutches do not have this feature.
Both have 4spd trannies and parts from each of them will swap out but to get the most out of either of them you need the big valve head and a big bore kit and bigger carb. You can get 12-13hp easily out of either of them but it will be cheaper to get it out of the lifan b/c it already has the head you need. Either way you go, you will need an updated shift star for the shift drum to clear up the false neutral problem. They tend to go to neutral when shifting from 3rd to 2nd b/c of a poorly designed star and weak detent spring.
And both can be started in gear if you crash and need to get going fast. The crank mounted manual clutches do not have this feature.
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OUCR250R said:
Do you have the 1 down 3 up tranny or the 4up?
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They aren't as prone to the faulse neutral problem. I was speaking of the 1 down 3 up trannies. The star is totally different on that setup.
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I have a 138 only ran it once, took it back out and put my ssr 86 back in it for now. anyone know much of what to do to them as I want to go thru it. I already have a oil cooler for it????
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boogie_man said:
why did you take it out?
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Danman2540 said:
I was running on break in with out a cooler (taken it easy) it started to sputter but it was a fouled plug. I would like to go thru it and do it up right before putting back in. WHAT VALVES/SPRINGS/PISTON/CARB will go on it nicely ???????
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110rider said:
Yes I have been told to RUN A COOLER !!! if riding hard. Anyone know the bore and stroke of the 138cc Lifan ????
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[/QUOTE] Anyone know the bore and stroke of the 138cc Lifan ????[/QUOTE]
54mmbore 55.5mm stroke
54mmbore 55.5mm stroke
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Anyone know the bore and stroke of the 138cc Lifan ????[/QUOTE]
54mmbore 55.5mm stroke[/QUOTE]
Hey thnx, you know much about the head ??? Valve/Cam ??? Anyone?
54mmbore 55.5mm stroke[/QUOTE]
Hey thnx, you know much about the head ??? Valve/Cam ??? Anyone?
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boogie_man said:
54mmbore 55.5mm stroke[/QUOTE]
Hey thnx, you know much about the head ??? Valve/Cam ??? Anyone?[/QUOTE]
27/23 Bigvalvehead ....71mm cam....crappy gearbox:wink:
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