PX 125 Disc 2001 recommissioning after being stored...

[wadsleyblade]

Evening all,

I have inherited a PX125 Disc from my son. Its been sat in the garage for a couple of years unused so I had a go at restarting it today. Too the carb off and drained all the old stale fuel and gave the carb a bit of a clean. Put it back together and like an idiot I put the stale fuel back in!! Thatll teach me to have two green fuel cans...  At least i know i can get the carb off easy enough, so will do the same again in the next few days but ensure i put fresh fuel in!

Anyways, i attached a new battery, stuck a new spark plug in, (after putting a bit of fuel in the spark plug hole first) and tried the electric start first. No luck with the electric start, but theres a clicking sound just behind the battery when i press the electric start button. All the connections behind the battery tray seem sound, nothing loose. The 7.5 fuse located here checks out ok. Can anyone give me clue on what to check next for the electric start? Ive cleaned any earthing points I can see, along with the connection to the starter. The horn works but the lights / indicators / fuel gauge dont (Not sure if this is normal or if they only activate after engine started??)

After that i tried the kickstart. The engine started and revved for about 30 secs or so then died. I noticed the rear light flickering while kickstarting - dont know if this is a good or a bad thing??


I'm not clued up on electrics so could do with a few tips on what to check next, am sure theres a wealth of knowledge on here. Thanks in advance,

Dave  

[alan34]

Hello there.your lights clocks will only work when engine running.the clicking sound could be a relay or the starter motor hasn't enough power to turn motor over clean connections etc I would put new juice in it and kick start it for now. now if it runs take it from there put a new plug in change oil etc good luck with it let us know how you get on cheers alan.

[alan34]

Hello there forgot to say if it's a new battery has it been fully charged.when you hear clicking from the elec starter it's a sighn the battery is flat.as there is not enough power to spin it.cheers alan.

[gpowell]

A PX125 1981 is not a factory disc bike, but as you have a battery im assuming the 1981 is a typo
Good points on the battery above but dont worry to much at this stage you can put a battery boost pack to it later

Look to get it running on the kickstart.

Please dont take this tbe wrong way... Is the fuel turned on? There are two tap types and they work slightly different. Yours should only have on and off, if disc. Though not inconceivable to the on off res tap

Have you checked spark is strong and fuel is flowing into carb, turn on and crack banjo. Then chech float chamber is filling. Check fliat and needle and the pilot jet
Try it with carb top and filter off.
Carb might need more cleaning, possible ultrasonic. Often the fuel passages get crudded up.

Check choke is operating correctly


The fact it fired with petrol in barrel is a start.

Dont worry about the fluckering light when you trying to start it, its just power going to it. Just turn them to off

Recommissioning is hugely rewarding but can frustrating while doing it.

Good luck

[wadsleyblade]

Thanks for the replys and tips...

My Mistake - the scoot is a 2001 with a 2005 donor engine. (Donor engine with very little warranted miles). 

The new battery is reading 12.53v on my meter, so im thinking its charged OK (although shop only took 2 or 3 hrs to charge it?)

 The clicking i can hear is coming from the starter relay - just been looking at how to test relays on youtube, so will have a crack at this later today (when ive obtained a couple of crocodile clips).

Fuel tap was deffo turned on, (pointed toward engine ON / pointed away from engine OFF / Reserve UP is what i was always led to believe??) 

Anyways, ive taken the carb apart again, removed the 3 jets and cleaned them in a little ultrasonics cleaner ive got. Unfortunately, when replacing the carb ive knackered the fuel pipe.... its like Billy Smarts circus in my garage! Looking on the bright side its probably a good thing - its fairly brittle and broke in another place fairly easily. So, have taken the fuel tank out this morning, came out fairly easily - hoping its just as easy going back in! Will try and get a new fuel pipe later today.

Float/needle in carb looks good, was filling ok. i replaced the filter while i was at it.

Ive been told there may also be a 'permissive switch' under the horncasting for the starter? Have never heard of these before so will have a look at that also.

Will let you know how i get on when its back together again...

[wadsleyblade]

Fuel tank reinstalled along with new fuel pipe - (new fuel pipe took some reattching to carb - In the end I used a heat gun for about 20 or so seconds to soften the end of the pipe up so i could get it to fit).
Carb reinstalled after spraying everything with carb cleaner and blowing through with air from a dive cylinder. Electric start worked first two times but then packed in again. (I still think it may be starter relay, although this tested ok with multimeter). Ive been told that the 'permissive switch' I referrred to in last post is only on the 200 models, but havent checked yet.
Engine fired first time on kickstart. It ticks over ok but only when the choke is still out about 10/15mm. If i push the choke fully in then the engine stalls.
I made a tool to access the mixture screw, as its obscured by starter motor body!..... just bent a 7mm spanner over at 90 degrees (warmed it up using a blowtorch and bent it using two pairs of mole grips). Then added 300mm of 15mm copper pipe to the end of it by hammering it on.

Whats the rough starting position for the mixture screw and idle screw please? (Like an idiot, i never checked position before dismantling)
Is there an idiots step by step guide to setting up? How long should i leave it idling with the choke pulled out slightly before its warmed up enough to start attempting adjustments?
Is there perhaps a reason it idles ok with the choke slightly out ?

TIA

Dave

[alan34]

Hello there leave elec starter till later to solve. mixture screw is two and a half turns out from fully in that should get you about right.when bike will only run with choke sounds like jet is blocked in carb maybe try a new one to make sure it's right size.if you look on previous replays on this site others with same prob have been helped with jets etc.good luck cheers alan.

[wadsleyblade]

Thanks Alan -

Update ... scoot running nicely on tickover with choke pushed in but wont rev, just bogs/stalls. If i pull choke out i can then rev it nicely.
Tried dozens of positions with mixer/ idle screw but no joy.
Any suggestions please??

[gpowell]

CDI breaking down or carb knackered. I chased a similar issue years ago on T5 with spaco carb.
Carb swap cured it.... Spaco SI carbs were for 50£ then... Alas not now

[wadsleyblade]

Aug 17, 2024 10:14:07 GMT gpowell said:

CDI breaking down or carb knackered. I chased a similar issue years ago on T5 with spaco carb.
Carb swap cured it.... Spaco SI carbs were for 50£ then... Alas not now

You were right g,

Swapped carb out and it cured it. Ticking over and revving nicely now. 

Back to the electric start problem...

Have checked relay switch with multimeter which suggests its ok. Will probably get a replacement to make sure, as not sure if the check is 100% reliable.

[gpowell]

Excellent... A tick(over) in the box!!

Best of luck with starter motor.

Ive very little experience with them. Only time was i did a swap on seized one for someone. Used an RMS one, was a good fit etc.
Not seen the lad for years, so no idea of its longevity