Lifan 1P54FMI

Find deals on amazon
Shop deals on ebay
Advertise with us
Mini Dirt Bikes & Pit Bikes Forum

Help Support Mini Dirt Bikes & Pit Bikes Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
R

Robbo_

Member
Joined
Mar 14, 2016
Messages
16
Reaction score
0
Gday people,
The motor has a serial number as above, 3 forward 1 reverse geared, electric start and auto clutch. Problem -turns over, nearly starts and then just seizes up. If I remove magneto cover I can free it up by hand but does the same when cranking it over again. Could this motor have a bent crank or something?
Any clues would be much appreciated I have checked timing chain, valves.
Cheers Robbo
 
Welcome to Minirider's.

First up, drop in here and introduce yourself


Did you check the valve/rocker clearance's ?
They should be .003" on the inlet, and .004" on the exhaust side (must check/adjust it at tdc on the compression stroke)
It may have had the clearance's done when the engine wasn't at tdc on the compression stroke.
If this is the case then it may have bent a valve ?

Cheer's, Craig
 
Thanks Craig,
My name is Robbo thanks for your reply. Yes there is valve clearance and valves seem to opening and closing ok.
 
I did try the introduce yourself "here" link but it seemed to go into someone else's page?
 
Robbo_ said:
I did try the introduce yourself "here" link but it seemed to go into someone else's page?
Click to expand...

That link work's for me? you just need to go to the last page and post there
When you checked the clearance's, was that at TDC on the compressiom stroke?
With the flywheel T marking lined up at 12 o'clock in the case, and the gear gear marking lined up at 9 o'clock in the head
When it stop's and sieze's, what position is the flywheel at ?
 
Ok. Again many thanks. I have stopped work on the motor for today but will look at it tomorrow with your questions in mind.
 
Hi Craig,

Checked timing etc. again.. Looks like the cam chain has jumped a tooth somehow? I have a photo but alas finding it extremely difficult to post it.
Any ideas?
 
Last edited:
image.pngimage.jpeg

BINGO!
image.jpegimage.jpeg

Does the 124 mm written on the barrel mean this motor is a 125 or is this the stroke length?

Cheers for any help
Robbo
 
Last edited:
The 1P54FMI mean's, 1- Single cylinder, P- Horizontal, 54- 54mm piston, F- Air cooled, M- Motorcycle
They have a 54mm piston and 54mm bore = 124cc
Most engine's are slightly smaller than their marketed size, eg 125cc

So the cam gear marking is just above the 9 o'clock line in the head.
That is ok, the timing chain tensioner is oil fed so when it's running the bottom of the chain tighten's up a bit and the marking's will be lined up.

Is that where the engine stop's each time you kick it over ?
Might just be because it's on the compression stroke ?
Can you turn the flywheel over anticlockwise by using a 14mm socket on the flywheel nut, and it'll go past this point ok ?
 
Thanks for that info- great stuff. Just got home and will check out and get back.
Cheers
 
Gday Folks,
Serviced the motor and did a bit more trial and error work.
Motor turns over fine with or with out spark plug or stator.
I have checked all wiring and that looks to be in all the right places.
When I connected the wiring up the motor started, ran and stopped.
When I tried to start it again it would not turn over.
Could this turn out to be an electrical problem maybe?
PS should the earth wire from the coil be connected to the cdi as well as the bike frame?
Again thanks for your time on this one. Robbo.
 
Yeah they are normally connected, coil earth to cdi earth, and reg/rect earth.
Is your battery fully charged, eg above 12.6v ?

Have you trued running the positive lead from the battery direct to the positive starter terminal ?
 
I think I'd better explain exactly what the set up is with this crazy project and how I'm trying to get it running.
I'll do up a diagram of what I've got tonight - very simple and probably very wrong.
Previous owner was lets say "rough as" to be kind.
 
Ok so here's a diagram of how this motor is wired. Probably a far cry from what it should be.
Also, I have been starting it via a car battery +ve straight to starter motor and earth to frame of the buggy.
Is this ok or should I be using a battery rated for this system?
Thanks Craig
image.jpegimage.jpeg
Hopefully you can read one of these - let me know if not and I'll try again
 
Last edited:
Yeah the wiring look's ok, you need to run the earth off the cdi to the frame too.
And you're correct with the kill switch black w/white from the cdi, just need's to be earthed via a kill switch
It's fine to use a car battery if you have somewhere to mount it
You will need to add a reg/rect (half wave) to keep the battery charged

Have you cleaned out the carby yet ?
Pull the fuel bowl off, remove the jet's and poke a thin strand of copper wire through each hole.
Also check where the pilot jet screw's into the base of the carby, check that the small hole through into the bore of the carby at the bottom of the thread's is still open.
And remove the emulsion tube and give it a thorough clean too,
Dont forget to remove the mixture screw and spring then blow it all out with compressed air through the small port's on the air filter side of the carby and reassemble it.
Mixture screw should be set at about `1.75 turn's out (should start and run at this setting) then once it's running you can tune it from there.
Last thing, fit a decent foam pod filter to it like a Uni Filter, and use some spray on filter oil to trap the dust etc before it can go through the engine.
You may need to raise the idle speed by turning in the screw a little to get it to idle
 
Yes have cleaned quite a bit of crap out of the carbi. Will continue to tweek and adjust. Will also test all electrics as advised.
Thanks
 
Hi Craig, spent a bit more time on this little beastie today.
Adjusted valve clearance and moved the cam, sprocket and chain around to better line up with timing mark.
(You'll remember it was out by about 1 link). I was concerned that I may have, by removing the bolt that acts as a tensioner, really caused myself a serious headache but it seemed to come together okay.
And, well bingo!! She lives! I still can't believe that this being out of adjustment could cause a motor to stop dead like that.
Alls well that ends well I guess. I will keep you posted on the progress of the buggy rebuild if you like.
Thank you for your advice.
Much appreciated, Robbo
 
Last edited:
You must log in or register to reply here.

Latest posts

Back
Top