Lifan 150 gy - Backfiring

[swimfan99]

hi, i have a lifan 150gy and have had so many troubles getting it too run. just got it running today and idleing and whenever i rev it up abit and hold the revs it backfires.
im also after some info about if they are road registerable, and what you would nned to do as it doesnt have a compliance plate
can anyone help?

 

[SnItChY]

no comp plate = no rego unless made b4 1968 i think or maybe 1972 ?

either way if ya got no comp plate no rego

 

[swimfan99]

yeah cool thanks.
got any info on the backfiring

 

[roost666]

wind the air/fuel mixture screw all the way in then 2 - 1/2 turns out, see how that goes, what position is the needle set at in the carb?

 

[no_crf50_here]

Air leak after carbie
Valves may need adjusting
timing

 

[swimfan99]

i spent alot of time on the carb and engine top end, im sure its not anything like that. i suspect its a ignition problem, probably a stuffed c.d.i but not to sure

 

[swimfan99]

how do you adjust the timing?

 

[sean01]

yep id try a new cdi, coil, sparkplug cap and spark plug to eliminate those at being a problem.

but id also check the tappet clearances as no inlet clearance will pop thru the carb if its bad enough.

also im guessing you have had the top end apart?

if so are you 100% certain on your cam timing!!

 

[thump*140]

^^^^yeah what seano1 said... first port of call is to check and set your valve clearances... there is a good tute in the "How-to" section on doing them properly.
Then i'd be looking at what sort of jetting you are running... post them back in here, and we'll see if you are close to the mark...
What type of carby are you running? i'm guessing a "genuine" Mikuni 30mm (26mm true diameter) and these have a tendency to just up and cack themselves...

 

[bulldog93]

how do you adjust the timing?

1) Take off your cam sproket cover.
2) Take off the cam sproket and timing chain.
3) Take flywheel cover off.
4) Line the 'T' mark on the flywheel at 12 o'clock. There will be a mark on the engine.
5) Line the cam sproket at 9 o'clock.
6) Put chain back on re-check that everythings where it's surpose to be (with the markings).
7) Replace all covers.

 

[thump*140]

or you can use the link below...

clicky clicky

http://www.miniriders.com.au/motor-tutorials/24347-how-set-timing.html

 

[swimfan99]

yeah ive had the rocker cover off and adjusted the valve clearance i put inlet at .06 and exhaust is .08 but yeah it idles fine and doesnt have a problem till i hold it reving might try timing or cdi

 

[thump*140]

valve clearances might be a bit big mate...
Try .003 for inlet, .004 for exhaust...
Ignition timing wont be adjustable i dont imagine, unless you have the ORK on it..
what sorta carby are you running, and what are your jetting specs?

 

[DvDRip]

yeah ive had the rocker cover off and adjusted the valve clearance i put inlet at .06 and exhaust is .08 but yeah it idles fine and doesnt have a problem till i hold it reving might try timing or cdi

dude that's WAY too much clearance! .003/.004 is the way, and that's thou not mil

 

[swimfan99]

i ment .006 and .008 its running a dekni pz27 and wouldnt know about the jetting thats set up

 

[thump*140]

yeah too much valve clearance... also symptoms sounds like its running lean... maybe try dropping the clip a couple of grooves on the needle.