Lifan 150cc 3rd gear gone

[aus_yzman]

My Lifan 150 gearbox is missing 3rd gear , when shifting up or down 3rd is now neutral.Is this likely to be a broken gear ?

Cheers

 

[sean01]

could be a couple of things mate.. but most of the time its a worn dog on a gear...
got the same problem with my wr450f (5th gear gone)

sometimes tho it can be a worn shift drum or selector fork, or it can simple be something has come loose on the shift drum

 

[aus_yzman]

Ok thanks Sean bike only done 15 litres of fuel . I am considering buying another new engine and repairing the lifan for a spare.Any advice on which new motor to buy that has a stronger g/box and is reliable with similar performance to a stock 150 lifan ? From reading other forums it seems common for lifans to lunch 3rd .

 

[motovert24]

you've broken 3rd gear
i've done it 3 times last time was more then 1 gear too

 

[sean01]

gearbox issues in china engines arent really brand related...
they all share an issue or 2 but most the time i think its manufacturer/assembly related.

i know of plenty of lifan 150's that are faultless as well as 155z and yx140's and so on,
but i also know of plenty of the same with issues..

so i think you just got unlucky with that engine... or maybe you are using an incompatible oil

you should just pull it down starting from the clutch side and have a look as you may find it to be something obvious.
like bent gear lever shaft
loose gear drum bolt above the front sprocket or even the shift star...

 

[motovert24]

your better off with a new engine i think
depends what you did a "gearbox cost about 350 and fitting on a crf style 125"
as much as a new jianling 125 and mabye some others

i just got a new gpx 125 coz i broke 2nd 3rd and 4th on my old one :LolLolLolLol:
and i rode the gpx for like 5 weeks and 3rd and mabye 2nd gear went coz of a sprocket breaking which i've seen and heard shouldn't break the gears in a gearbox

the reason why mine broke is because when they built it they didn't shim (don't think that how its spellt) the parts right so there prone to breaking as sean said
then you have to wait for parts for weeks as im doing now :frustrated:

 

[sean01]

your better off with a new engine i think
depends what you did a "gearbox cost about 350 and fitting on a crf style 125"
as much as a new jianling 125 and mabye some others

i just got a new gpx 125 coz i broke 2nd 3rd and 4th on my old one :LolLolLolLol:
and i rode the gpx for like 5 weeks and 3rd and mabye 2nd gear went coz of a sprocket breaking which i've seen and heard shouldn't break the gears in a gearbox

the reason why mine broke is because when they built it they didn't shim (don't think that how its spellt) the parts right so there prone to breaking as sean said
then you have to wait for parts for weeks as im doing now :frustrated:

gearboxs are no where near that much... dont quote to people from your ripped off experiences..

complete gearboxs are around 100-150 depending what you buy..
GEUNINE LIFAN 140 CC 150 CC ENGINE ALL UP GEAR BOX ASSY - eBay, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 23-Jul-10 20:33:11 AEST)

also would maybe need a shift drum but i cant find a listing for that..


and mv yours broke because of the rear sprocket failure which would of bent the hell out of the counter shaft...
and im guessing this sprocket failure was from a very over tensioned chain..

so i dont know who told ya about the shim story..

EDIT

also mv id be surprised if a zonger 140 gearbox didnt fit yours..

 

[motovert24]

Including fitting which I dout it would cost that much anyway

dhz said they need to order parts for the GPX coz it's different?

 

[sean01]

GPX is a rebranded YX
and zonger is basically a glorified YX

 

[aus_yzman]

Ok pulled the clutch cover off and found 2 pieces of 3rd gear looks like the dogs. Am I right in assuming there is 3 in total.Here is a picture of the 2 pieces we found. Hows does a GPX 125CC RACE ENGINE, HIGH COMP PISTON, RACE CAM go compared to a 150 lifan? Or what engine would you guys recomend ? I suspect the gear broke due to my son popping the clutch in 3rd exiting loamy berms thinking he was in 2nd a few times.We thought the g/box could handle slipping the clutch in dirt no worries.Grrr!!

Thanks for all your help guys

 

[sean01]

yep they look like dogs. and usually there is 3 or 4 dogs...

the gpx 125 i would consider a down grade(power wise) from a the 150.
id say your running to tall of gears for dirt work if this happened from what you said..

replacing the gearbox isnt really all that hard mate,
you would need the gearbox i listed above as well as a gasket set, ring set and clutch and magneto tool.
you would also need to hone the cylinder

 

[aus_yzman]

GPX125 doesnt sound too apealing then I thought it might go great with the big cam hi comp piston & 13,000RPM redline lol .Bikes gearing is 15/39t , I will buy that gearset and the tools,piston rings etc you mentioned.

Cheers

 

[brett3]

ive just had a simaler problem, i broke my clutch lever, so ive been flatshifting (up and down)
all gears are good on the way up, shifting from 4th back to 3rd it seems as if it shifts too far, because you give it a little tap up and it clicks 3rd...

now ive let the bike cool down overnight,
i can only grab 1st, it wont shift any higher than that..
leaver moves but it doesn't seem to be moving anything inside the box, might be jamming before it catches the gear?

Bike is a DMX with a rebuilt 150cc YX motor..

 

[motovert24]

GPX125 doesnt sound too apealing then I thought it might go great with the big cam hi comp piston & 13,000RPM redline lol .Bikes gearing is 15/39t , I will buy that gearset and the tools,piston rings etc you mentioned.

Cheers

the GPX is an awesome engine...
very fast too