lifan 125 gear box

[josh193]

hi i am putting a new gearbox in a lifan 125, as 3rd gear was rewined, now when i put it together whilst still out the frame, the gearselector doesnt select the gears, it clicks up and down but the drive sprocket just spins freely,

need help asap

 

[sean01]

turn the front sprocket while changing the gears, and do you have the clutch installed while checking the gears?
if thats no good then something isnt installed correctly

 

[josh193]

gh

turn the front sprocket while changing the gears, and do you have the clutch installed while checking the gears?
if thats no good then something isnt installed correctly

yeh i dont put it in the frame because i try it all first and see if everything works. if i put it in the frame i will have to pull it allout again if somethin is wrong.

and yes it does have a clutch, but i dont conect it on the engine, wheen i spin the front sprocket and change the gears it just spins, it is meant to lock isnt it

 

[sean01]

yes it is meant to lock, which is the reason i asked if you had the clutch assembled in the engine because if it wasnt then it would turn freely..

its hard to say wat's wrong as the gearbox's are pretty straight forward and basically fool proof.

was it the same pattern gearbox you installed and what parts of the gearbox did you actually replace

 

[josh193]

.

yes it is meant to lock, which is the reason i asked if you had the clutch assembled in the engine because if it wasnt then it would turn freely..

its hard to say wat's wrong as the gearbox's are pretty straight forward and basically fool proof.

was it the same pattern gearbox you installed and what parts of the gearbox did you actually replace

i only put the casing on and the flywheel, clutch and stuff like that i dont put it all together like putting the head and barrel on, so than if i have done something wrong i can just take the clutch and flywheel off that pull the casing off. instead of pullin it all down and trying again. and i just put the gear lever shaft in and try the gears.

so are u saying if i install the clutch the gears should lock when i gear up instead of just free spining?

and i put a whole new gearbox in.
thanks

 

[sean01]

the sprocket only locks up because it tries to turn the crank and piston which in turn builds compression.

so basically put all the bottom end back together minus the clutch cover and then the crank should turn when you spin the sprocket in gear..

post a pic of how you test it (clutch side)

 

[josh193]

.

the sprocket only locks up because it tries to turn the crank and piston which in turn builds compression.

so basically put all the bottom end back together minus the clutch cover and then the crank should turn when you spin the sprocket in gear..

post a pic of how you test it (clutch side)

does the gears have to be in like neutral or do they just go in anyway, anddoes the gear selector gotta go in a certain way?

 

[sean01]

no it can be installed in any gear.

wat are you calling the gear selector (just so i can give the correct answer)

 

[josh193]

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no it can be installed in any gear.

wat are you calling the gear selector (just so i can give the correct answer)

this is the gear selector

 

[sean01]

ok thats the gear drum and the forks looking things are shift forks..

the forks and can only go in one way, well actually every thing can only go in one way..
but like i said earlier, make sure you have the small bolt in the gear drum that goes in above the front sprocket

 

[josh193]

.

ok thats the gear drum and the forks looking things are shift forks..

the forks and can only go in one way, well actually every thing can only go in one way..
but like i said earlier, make sure you have the small bolt in the gear drum that goes in above the front sprocket

the bolt with the cap that covers it, is it an allen key?

 

[sean01]

yeah some have an allen key some have a 10mm head and since yours is a lifan it may have a funny shaped brass looking washer..
if this bolt isnt done up the shift drum will float around and gears will muck up

 

[josh193]

.

yeah some have an allen key some have a 10mm head and since yours is a lifan it may have a funny shaped brass looking washer..
if this bolt isnt done up the shift drum will float around and gears will muck up

yeh it has a goldish washer on the back, and yeh i will try it again. so if i put the engine back together it should work

 

[sean01]

should......

 

[josh193]

.

should......

this is how i test it

 

[sean01]

if your testing it like that you'll be able to see each gear change the ratio of the sprocket..

turn the input shaft by hand and select a gear, sprocket will turn. now while still turning the input shaft select the next gear up and you notice the sprocket starting to turn faster..

just make sure you can select every gear including neutral..

 

[josh193]

.

if your testing it like that you'll be able to see each gear change the ratio of the sprocket..

turn the input shaft by hand and select a gear, sprocket will turn. now while still turning the input shaft select the next gear up and you notice the sprocket starting to turn faster..

just make sure you can select every gear including neutral..

i tried it and the gear shit lever that changes the gear drum, it clicks in neutral clicks into 1st and theen it doesnt grab on them little teath on the drum

 

[sean01]

is it the same gear drum that was originally in it?

 

[josh193]

.

is it the same gear drum that was originally in it?

yes, i think it is normal because my motovert 140 when its turned off and just sitting there i click it up ounce than try again does the same thing, until i move the bike up and down than it engages.

 

[sean01]

well your not really reading what im saying, what you have just said above coincides with my last bit of advice.

if your testing it like that you'll be able to see each gear change the ratio of the sprocket..

turn the input shaft by hand and select a gear, sprocket will turn. now while still turning the input shaft select the next gear up and you notice the sprocket starting to turn faster..

just make sure you can select every gear including neutral..

you have to be turning the gearbox input shaft or front sprocket whist at the same time selecting gears..
these are non syncro gearboxs which means the gears wont full mesh untill the shafts have turned a bit, and if they dont fully mesh then theres only 1 other gear it will select and thats the gear you just came from..