125cc Semi Auto, Electric/Kick start no start

[Tipene]

Hi Guys,

This bike is doing my head in!

So I bought it for $200 described as needing tlc to get it running, as in fuel clean oil change etc, simple stuff.

Bike is a 125cc Semi Auto with electric start and kick start backup.

First thing I did was clean the carby out, put fresh fuel in and went to start the bike with electric start....absolutely nothing happens, no click no nothing,

First thought is CDI so I grabbed a working CDI and put it on the bike, still nothing

Second thought was kill switch so I cut the kill switch wire to bypass the kill switch, still nothing, then I replaced the killswitch with a working one and reconnected the killswitch wire to the CDI....yep you guessed it still nothing. Even replaced the spark plug but because I can't turn the engine or anything I can't even check for spark, this is about as far as my mechanical knowledge goes, I have had some people ask about the stator but am unsure how to check it or what to look for once I get it out.

Tried to kick start but it is jammed, tried to take right crank case off, undid all the screws I could see and still unable to remove right crankcase cover, as if it is painted shut, or I'm missing a bolt/screw somewhere....

Some help would be greatly appreciated before I take it to a mechanic, not really wanting to pay $80 odd dollars an hour, before I know it I'll have spent the same amount as a brand new bike.....

Cheers in advance.

 

[Tipene]

Forgot to mention, when messing with the killswitch I discovered one wire went back to the brake lever, indicating it has an open switch unless brake is applied, so tried again with brake applied and still nothing, I actually thought it was gonna start when I found that....DAMN! Out of ideas....

 

[motodevo]

Before you go any further, check the motor isn't locked up. With an elec start the easiest way would be to take the round cover off the chain side that gives access to the nut that holds the flywheel on the crank and put a socket on it and see if you can rock it back and forth. If not the rings are probably stuck to the bore, it only takes a tiny amount of corrosion to make them stick. One motor i had was that stuck the splines on the kickstart shaft twisted trying to kick it over, however 30 mins spent whipping off the head, barrel, wiping away all the debris and reassembling and the motor was running like new.
The clutch side cover has 2 dowels that keep it all aligned when tightening up the cover, once i take all the screws out i just give it a few taps with a rubber mallet, in the top corner near the top engine mount and the front bottom corner (thats where the dowels are)

 

[Tipene]

Thanks Motodevo,

I'll give that a go in the next couple of days and let you know how I go, really appreciate you taking the time to offer some advice.

 

[Tipene]

Before you go any further, check the motor isn't locked up. With an elec start the easiest way would be to take the round cover off the chain side that gives access to the nut that holds the flywheel on the crank and put a socket on it and see if you can rock it back and forth. If not the rings are probably stuck to the bore, it only takes a tiny amount of corrosion to make them stick. One motor i had was that stuck the splines on the kickstart shaft twisted trying to kick it over, however 30 mins spent whipping off the head, barrel, wiping away all the debris and reassembling and the motor was running like new.
The clutch side cover has 2 dowels that keep it all aligned when tightening up the cover, once i take all the screws out i just give it a few taps with a rubber mallet, in the top corner near the top engine mount and the front bottom corner (thats where the dowels are)

Okay so I did as you suggested, and took the case off to access the flywheel, and was able to turn the nut clockwise for a little bit before it would stop, is this normal? turning anticlockwise was no problem, I noticed that when I did turn it clockwise it seemed to free up the kickstart and I was able to push it down all the way but only once then it locked up again.

While I had the stator off I checked it and not sure if I could spot something out of whack but put a multimeter on and checked earth(green)/Red,Black wires and got a reading of around 400ohms which from another thread on stators is good, but I also checked the green to white wire and where I should get 130ohms am only getting 70-80ohms what does that indicate? Do I need a new stator, would that be why I don't get anything when I press the ignition button not even a click? or something else?

 

[motodevo]

Stator readings should be fine.
Sounds like something is stopping the piston going all the way up the bore. Could be corrosion on the bore, could be a bent valve not closing and the piston is hitting it, or the timing could be out so the piston is out of sync with the valves and are making contact stopping it from going all the way up.
The reason your not getting a click is probably the same reason you can't kick it either, something is stopping the piston from moving
I'd be pulling off the top end to check it out

 

[Tipene]

I replaced the stator anyway picked it up for $15.00 from blygo after work, and immediately got a click, I then put the battery on charge and went out to get a few things, got home and put battery back in and now I have spark, put spark plug in and it is turning over, but not starting, I feel like I've accomplished a lot today going from dead to having spark....so close, now I need to figure out why it's not starting....I somehow got the kickstart to compress a few times before jamming again so unsure whats happening there.....next step?

 

[motodevo]

If you have a can of aerostart or start ya bastard, pull the plug and spray a little into the cylinder through the spark plug hole, put the plug back in and hit the starter.
If you get it to run or even just pop then you probably had an issue with getting fuel from carb (blocked pilot jet). If you dont even get a pop, chuck the plug for a new ngk (chuck it if it isn't brand name, chinese plugs are ****), theyre only a few bucks, i buy them a few at a time, just because a plug fires when you test it doesn't mean it is good enough to fire under compression, wasted ALOT of time in the past with dodgy plugs

 

[Tipene]

Really appreciate the help Motodev,

I'll get a can after work today along with a couple spare plugs, I always like to have spares of everything when away for a weekend, because ya never know, and fingers crossed we can get it to fire up, if not could it be a timing issue? I had to take the front part of the engine off because the manifold intake screws had damaged the case and only one was holding it on, so got a spare and replaced it, but had to take the sprocket off without realising it had timing marks on it.

 

[motodevo]

If you have taken the head off there is def a possibility that the timing is out. Pretty easy to check. On top of the stator cover there should be a round cover the size of a 10c piece, take it out and spin the flywheel until the T mark is lined up in the middle of the hole (usually a notch to line up to inside. Once the T mark is lined up, pop off the round cam cover on the side of the head (it is held on with a long 10mm bolt from the opposite side of the head), if the timing is correct the little circle on the cam gear will be at the 9 o clock position, there should be a notch or marker on the inside of the head to indicate it exactly. If the T mark on the flywheel is on its notch and the circle on the cam sprocket is on its notch your timing is correct. If not, unbolt the cam gear, take the timing chain off it (without letting it drop into the cylinder), put the cam sprocket back on with the bolts and turn the gear until you line it up with its mark, then remove it and put the chain back on the sprocket and bolt the sprocket back onto the cam taking care to keep everything aligned correctly.
Note if the timing is more than a tooth or two out you may have turn the flywheel 180° so the piston doesn't hit the valves whilst you align the top end

 

[Tipene]

Took the head off and found that one of the valves has snapped...there lies my problem! so need to replace them and check the piston. Probably should have checked those first, and the timing was way off, which is probably what snapped it, no wonder why the flywheel was never turning fully...lesson learned! Now what I should have asked earlier is that on this semi auto there is the wires coming out of the stator but also wires coming from just above the chain sprocket to the right of the stator which has a 6 pin plug on it like that on the CDI....it's not pligged in anywhere...where is this meant to go and what is it for?

 

[motodevo]

There is sometimes cables coming out if a round rubber an inch or two above the sprocket. They are for gear indication, (N1234). Not required to make it run

 

[Tipene]

Thanks mate, I've replaced the valves, taken me a few days whilst n using uncle google on how to replace, checked the piston and all seed fine, triple checked everything I done and was still anxious about starting in fear I wool damage m...checked everything another 2 times....paranoid! Once I was brave enough turned it over, almost started...kept trying and was just sooo close,I swapped carby with a working one and it started, woohoo happy days, just had to adjust the idling screw and bike running fine, I can't THANK YOU enough mate your help it has been worth key stroke

 

[motodevo]

Good to hear