Urgent changing cams

[linkenator]

I have removed the head from my lifan 140cc and i cant work out how the remove the cam that is in the head currently
any help is much aprecciated

 

[coolmodee01]

loosen off the rockers and you should be able to knock out the cam gently from the spark plug side

them just slide the new one in

i think haven't done it in ages

 

[user 12599]

yer yeh loosen the rockers or tappets it the correct name i think get 1 of the bolt screw it into the cam and use the bolt to pull it out, if you know what i mean.

 

[thump*140]

The lifan 140 has an anti-kickback mechanism, and if memory serves, that was what had me scratching my head for a bit until i figured out it needed to be held "open" to remove the cam... it is a weird spring looking "latch" type thing on the sparkplug side of the cam... removing the cam is nearly a job for three hands at once...
more than likely, it will be the anti kickback mechanism that is making the cam hard to remove...
hold this open, the cam *should* slide out...

 

[linkenator]

thanks for the info
but i couldnt find the kickback mech
so i just left the stock cam in there
Cheers

 

[bulldog93]

The lifan 140 has an anti-kickback mechanism, and if memory serves, that was what had me scratching my head for a bit until i figured out it needed to be held "open" to remove the cam... it is a weird spring looking "latch" type thing on the sparkplug side of the cam... removing the cam is nearly a job for three hands at once...
more than likely, it will be the anti kickback mechanism that is making the cam hard to remove...
hold this open, the cam *should* slide out...

Actually not that hard..You don't need 3 hands just yours and your teeth haha

Here I did a quick tut on it:
http://www.miniriders.com.au/mini-tutorials-how-s/24595-tear-down-bike-parts-completly-3.html

Should come up on page 3 if not its on page 3 the info your looking for..hope it helps.

EDIT: took a paragraph out of the thread

The rockers and cam:
After you take off the caps/covers turn the head so that that the bearing(where the cam sprocket was) is facing down. Now get some needle nose plyers or similar and take out the rocker pins in the bolt holes. Undo the little bolt that holds/adjusts the rockers/valves(1x 10mm nut, one on each rocker). Then you can push out the cam. NOTE: I haven’t pulled the valve springs out.

if you take out the rockers then the anti-kick back mech will fall out..its just like a washer that connects to both rockers and then push the cam out.

 

[linkenator]

i dont have that side cover on my sparkplug side so i couldnt see how i could take out the rocker pins
or for the lifan is it just the kickback mech that stops the cam sliding out?

 

[sean01]

what do you mean..you dont have that cover on your spark plug side....are you saying your engine doesnt have the cover?

if so i think ya better put some pics up

 

[linkenator]

no its fine i was looking at the head the wrong way...my bad
but ill probs just try it another time

 

[headsmess]

is it done yet?

ah well, everyone explained it... you just pull the rocker pins out...pliers, lying it on its side and tapping it, wedging a pencil up them, sometimes they even have a thread so you can get a bolt into em...whatevers easiest


i still dont see how themountain can do it without pulling the head off completely(or so he says)... the cylinder studs act as the retainers.... that side covers little more than a basic oil cooler(it is an oil gallery, after all...with fins )

then when reassembling, set the valves before putting the head back on...just a lil bit easier then...

 

[sean01]

i spose if you unscrew the rocker adjustment screws all the way out you may get it by turning and pulling at the same time.....
couldnt say tho never tried it that way

 

[headsmess]

mmmm, with stock cams, its possible...with hi-lift...nope.

 

[linkenator]

Hi all im glad to say i got the 7mm lift cam in after slaving away for hours (about half an hour)
got the head back on and set the valve clearances. The bike idles in neutral but now when it is put into gear the bike konks out immediately after even without letting the clutch out.
i have my suspicions that it could be that the carby needs a tune but any info or advice is welcomed
Cheers

 

[china boy788]

hey, hows the bike now? did you get it going again after puting the cam in?

 

[sean01]

Hi all im glad to say i got the 7mm lift cam in after slaving away for hours (about half an hour)
got the head back on and set the valve clearances. The bike idles in neutral but now when it is put into gear the bike konks out immediately after even without letting the clutch out.
i have my suspicions that it could be that the carby needs a tune but any info or advice is welcomed
Cheers

yeah did you fix your issue with it konking out?

if not explain the problem a little more...it sounds like the clutch plates are stuck together..

 

[headsmess]

does it accelerate smoothly? when in neutral?

and it konks out IMMEADIATELY after putting it in gear?

check the spark while its in gear...my suspicion is the neutral wires hiooked up wrong and is shorting out the cdi...like a secondary killswitch... its the pale green wire...it shouldnt be attached to ANYTHING! ie, cut it if it is......