Lifan 125 kickstart issue, taking longer to kick over

[illville]

Hey everyone,
Just wanted everyones advice on why my engine is taking longer than normal to kick over now. hoping to figure this out so my son can start it himself again. Even i work up a sweat trying to start this thing. Doesnt like to idle much until it warms up either so you have to feather or hold the throttle until it does.

running a LIFAN 1P54FMI 125cc motor

Single cylinder, 4-stroke, 2 valves, OHC, air cooled, 125cc
Bore x Stroke: 54mm x 54mm
Dimension: 17"X11"X9"
Valve Sizes: 27mm intake, 23mm exhaust
Displacement: 123.7cc
Compression Ratio: 9.47:1
Carburettor: 26mm carburetor, Uni filter
Ignition: CDI, 12 volt, permanent magnetic stator
Maximum Power: 8.5 Kw DIN @ 9,500 rpm
Rated Power: 6.5 Kw @ 7,500 rpm
Torque: at least 8.8 Nm @ 5,500 rpm
Gears: 4-speed, semi auto clutch, 4 up shift pattern.
Gear Ratios: 1st 2.833:1, 2nd 1.706:1, 3rd 1.238:1, 4th 0.958:1
Final Drive: 14 tooth #428 front sprocket
Lubrication: 900ml, 10W/40 4-stroke motorcycle oil, pressure and splash
Fuel: Unleaded


I would say the motor has about 10 hours on it, definitely no more than 15 hrs. Everything is in great shape, oil is changed every other ride, i run premium 92 octane fuel. filter is cleaned and oiled regularly. bike is also cleaned after every ride.

I thought it could be the carb or spark plug but i just put a new NGK plug and new carb on and still takes forever to kick over. I used starter fluid to get it started and once it warms up it runs good and will kick over the first time when its been running, but when it cools back down we're back to square one.

I swapped the old CDI back in to see if it made a difference but still the same. Dont know if it could be the ignition coil which is new with the engine but it does have spark so im clueless! :huh

Appreciate any help you guys can give me

[chunky0071]

Check your Valves!

[Ride1Rob]

The valves on these lil motors don't wear fast at all. But it doesn't hurt to check them. One thing for sure is they don't like water. Was somewhat of a headache to start Jams after a cleaning as well. Off jetting could also be an issue on cold starting. Next time you start it let it sit idle for a few minutes. Pull the plug and check it and see what she's looking like.

[illville]

OK, thanks for the response guys.

As far as checking valves, can someone give me a little tutorial on this as i have never done it before and dont want to mess anything up.

[illville]

Also this is a pic of the Ebay special 26mm "Mikuni" carb im now running, it doesnt seem to have many adjustments besides choke or idle on the outside, i dont see a mixture "air" screw or anything else. I will say though that the throttle response is night and day and it did seem to wake the motor up a bit, when its running of course.

When i ordered the carb, the needle jet clip was on the bottom grove (6th) allowing more fuel, and when it finally did idle it was very inconsistent. It would idle smooth then hiss and rev high for a bit, then back down in a repetative process. also when i hit gas it would stay revved a bit even after i let of the throttle like it had extra fuel to burn. On a test ride the motor didnt skip a beat and it ran great with good response from 1st through 4th gear.

I relocated the needle clip to the middle grove, put in new plug and got it started again but there was alot of snap crackle pop as i revved it and let off the throttle, throttle response wasnt great and it didnt idle well. I did pull the spark plug after 3 to 5 minutes of run time and it looked dry as a bone and unused.

Keep in mind i was still having the hard start issue with the old carb that came with the motor before i swapped them. This motor never kicked over quick on a cold start but its gotten noticeabley
worse.

http://i42.tinypic.com/oirlhd.jpg
http://i39.tinypic.com/2dhbtr5.jpg

[illville]

Originally posted by chunky0071
Check your Valves!

:cool:

Watched a youtube "how to" on valve adjustments and went to it, put it back together after the adjustment and it kicked over and it fired on the the first try, the compression difference is huge, feels like it wants to kick right back at me lol. It idles perfect great throttle response, runs like a dream! The valve tic is noticeable compared to before the adjustment as i couldnt hear them before.

[chunky0071]

Those are Honda copy motors and they should have a little tick when running.