Lifan 140 Engine Problem HELP :(

[widger]

Hey guys

after wiring it all up and all, all starts...

I just have an issue with throttle on etc, i throttle on and its backfiring or popping!

and it just dies...

I dont have much idea on these bikes as of yet.. but it has an aftermarket CDI kit etc,
i was wondering with the mikuni carb 30mm i think, the overflow screw thing, does that have to be open or closed tight?..

the engine just doesn't sound smooth....

also, when i seem to put the choke on, it doesnt seem to have a huge problem in revs.. but it still makes that noise im not sure of! HAVE A LISTEN IN THE VIDEO!

cheers

VIDEO AND SOUND..

http://s1183.photobucket.com/albums/x466/widger20/?action=view&current=IMG_2554.mp4

 

[GooseMan]

I think one of the first problems is your carby, its a 30mm you say, thats a bit big for a 140cc, 160's with 184 bore kits can only just manage that size carby usually, you can give it a shot at tuning it if ya want but it may not tune at all, did that carb come with the engine? Also check all wiring to coil and cdi and spark etc are all clean connected properly.

 

[widger]

yeh i got it off a mate, but he said it ran fine when he had it.......
could this be the timing of anything at all?

to be honest im not sure what size carb it is..

I have all the earths and wired up etc, and it starts first time with choke on!

 

[8r3nd0]

Check ya valves mate also an obvious question does it have oil?. I know it is a simple question but it sound dry something is not quite right. How old is the bike?

 

[widger]

I changed the oil, so yep! i am good with cars, but i still have no idea on bikes yet!
he said the engine is really new, and looks it too...

so with the carb, the line that comes out the bottom, is that supposed to be open (ie overflow) or screw it in, and block it up? im thinking its ment to be open, allowing air in, if the float is set right??

oh and checking valves on these things. hard?

 

[GooseMan]

checking valves, easy ,check out the tuts on here for help. and that overflow should be closed, its only there to drain fuel from the carb when cleaning it, which is something I'd recommend you doing aswell, who knows whats got in there.

A 26mm mikuni is what should be on it or there abouts, also look at tuning tuts on here and have a shot at tuning it.
I you haven't touched the insides of the engine (i.e. cam chain etc) then the timing should not have changed.

 

[widger]

ok will do, it just doesnt sound right! haha!

ill have a look at the tutes right now. as far as i know the engine has never been opened..
does the aftermaket

I forgot to mention the inner rotor kit is also aftermarket.. will this affect anything??

 

[8r3nd0]

check the timing for sure.

 

[widger]

far out! haha, i have no idea on any of this as of yet...

which is ****, all i want is to have it run awesome haha, and no knocking sounds!

so do you suggest, value clearances, timing, and hmmm

 

[8r3nd0]

yeah mate unfortunately there's something going on and yeah it might be whats need to get it running awesome haha. To do the valves your basically one step away from checking the timing. Use the Miniriders search tab and remember google is your friend. Good luck mate

 

[rotn50]

Thats sound bad mate, as if something is loose inside the engine, maybe the oil slinger has come loose(or seperated into 2 parts) and is rattling on the side of the case(the clutch side), i have seen one 140 were the crank snapped were the slinger sits over it and still ran but was noisy as kinda like that, as for the IRKs dont be surprised if it doesnt last long. Maybe pull the clutch case off and inspect it after the other checks and adjustments have been made.

 

[widger]

hmm i see, i drained the oil because of the noise, and didn't notice any metal particles in the oil at all?
i just want this to run well..

kind pissed off at my mate, as he said it was fine..

 

[rotn50]

the one thing with 140s i have noticed(just my opinion) is they like hard riding but the engines cant handle to much severe thrashing, if the slinger has come loose or the crank snapped then you wont really find metal filings, it def sounds internal and maybe pull the ride side (clutch) case off and check for anything floating around in there.Hope ya mate didnt sell ya a dud as ive heard it before about how it was running fine when i owned it crap.

 

[widger]

yeh if he sold me a dud, ill let him know, or better yet, his mum! hahah its odd though, because when i rode it on sat, i can ride it up the street, change gears, through each gear, no prob, but when i gas it, it backfires and then let off and it dies.

 

[rotn50]

the only reason i mention internal probs is that the vid makes it sound like it is inside the engine and sounds pretty bad, but if the sounds im hearing is actual popping or backfiring like you mentioned then those IRKs can be a big prob at times, they can play up at all rev ranges to not running at all, does the vid sound different than being next to the bike??, i just dont want to mislead you with the wrong info

 

[widger]

the vid does sound louder i guess, its not super loud when you start it up, just not quiet! and me having it running and moving kind of seems like if it was internals it would be messed up already! haha

yeh i might order a IRK as a spare and try it, but no, the sounds are not popping and backfiring, thats only on throttle etc, so im thinking it could be a carb problem and a way to oiled filter, as it seems like it is!

but lets hope! ill clean the carb out tomo and air filter somehow, and see if it improves,

im guessing if not enough fuel goes through etc, it can run real rough etc!
i just think a clutch and or gears would be alot louder!

 

[8r3nd0]

Yeah start with the basics mate an over oiled air filter will bog like crazy, i would say fuel delivery problem.

 

[rotn50]

maybe order the std outer rotor kit instead of the IRK, there just problematic. good luck mate, hopefully you get a ride in.

 

[widger]

given up with the ****ing thing, pissed off at my mate, tried to clean carby out, now it wont run right at all.. got no idea about these things

wish some place in adelaide would do these things..

 

[iiTz CaMMs HD]

Dont know if this will help you but I had this problem a while back and I solved it... Check in your carb that it has the right spring for the throttle and also just clean it out, You'll have no problem running a 30mm carb I got one straight of the shelf and whacked it on (no tuning or anything) and the bike rode like A dream. But if you want the performance go for a 26mm and tun it up.