px 125 ? electrical problem

[sawdustcaeser]

Hello all,
please bear with the description.
My Px 125 was due an MOT.  Has been laid up in the garage all winter.  Throttle cable was sticking on.  I gave it some oil and it was better.  I took the headset top off and I could see that it was not returning to fully closed position.

I took it to my local scooter dealer for a service and MOT.
Firstly they said it was not the throttle cable but the mixture that was wrong and that the carb was loose.  Now I rode this scooter all last year with no problems.
Anyhow, serviced it and MOT's and initially it ran very well.

When I got home the indicators weren't working properly. The rear light had started to flash on and off with indicators.  They were working perfectly prior to taking to the garage. Phoned them up, said it was probably a loose earth.

Took it tonight to let them look at it.  Fuse was blown to the battery.  Put a new fuse it. Now front indicators work but back ones still off.
Rode it home, got a big backfire halfway home.  Then noticed the bike was revving high when I stop at lights etc. AND poor power pulling away/ jerky acceleration.

Bear in mind they charged me £180 for service and MOT.
Now the scoot won't tick over properly.

I phoned them back and they said they will look at it Friday but may need engine rebuild ? crankshaft oil seal gone if revs gradually increasing (there was a lot of oil on the engine block when I got home that had not been there before)

The garage are long established but I  have not had a scoot in years so can't vouch for recent quality of work.
May all be a co-incident.  Maybe the engine is dead and needs rebuild.
I am reluctant to take it back to them.

I appreciate that is a long and rambling story but does it ring any bells with anyone?
Many Thanks for any advice.

[doulsy]

have you tried ajusting the carb? its pretty easy, look it up online, think for a spaco carb you turn screw fully in then turn it out 1.5 times, if its a dellorto its 2.5 times, i might have this the wrong way round so check online first. if its reving really high like mad then it could be air leak. as for indicators see the sticky above.

[sawdustcaeser]

Thank you Doulsy,
I will try that eventually: however.....

I went to kick it over today and it will not fire.  Not only that, but I got a massive backfire.  My ear is still ringing! It sounded more like an electrical bang than a backfire.  Like a christmas cracker.

I think I need to back to basics on this.  It was fine before I took it in.
The electrics are strange, its a californian  import.  It's a PX mark 1 but has autolube.  It also has a battery.

For the service he said they changed oil, adjusted points, tightened carb and adjusted mixture.
It ran really well but with no indicators.
The fuse to the battery had blown.
It was when we put a new fuse in that it went bang and rode roughly.

The mixture may be wrong, but I am convinced the problem is electrical.  And I am crap at electrics.
I have a multi meter but don't know how to use it.

Is there a basics sticky on electrical testing?  I will have a look tonight for some articles on electrical system.

Dave

[doulsy]

no sure m8, i have a mk1 but its a non battery with no points, is your vespa a p125x? think only the p125x and the p150x used points, there is a few experts on here, someone should be along soon to help out, maybe pxguru, henri ore sime66.

[henri]

weird one, does sound like electrics/ignition problems .as its just been serviced i'd check the points gap as they might of slipped .as its a usa scoot they have different electrics ,could try looking/asking on modern vespa forum ,theres a fair few yanks on there .or ask jedihunter on here ,he's a "good old boy" from the mountains .H

[doulsy]

take it back to garage and ask them to check ignition settings, let us know how you get on.

[sawdustcaeser]

thatnks everyone,
i am not going back to the garage. I wish I had never taken it ! you live and learn.
I am going to check the points gap today and check for a spark. It won't fire at all now and every now and then goes bang !

I will let you know what I find.

[henri]

timing slipped , maybe , they shouldnt of had to pull flywheel to adjust points ,but if they did an didnt torque it back up enough .it would of moved an sheared the woodruff key .but my moneys on points slipping coz they didnt tighten the screw enough .H

[shipscat]

that to me sounds like a bad condenser or perhaps the condenser wire is chaffing on something
not sure about px with points ignition ?
can you post the engine number

[sawdustcaeser]

[sawdustcaeser]

OK,
the video in the last post is me cranking the scooter.  problem is I am not a mechanic. there is a spark but not all of the time and looks weak to me?
Does anyone have a comment?

Also when the piston is at TDC the points look closed.  I can't work out how to set the gap?
I can only see one screw but if you slacken it the whole points set moves.  Seems like the retaining screw for the contact breaker unit?  When you slacken the screw, gap the points and then tighten the screw, the points snap closed (with the piston at the top of the barrel).I cannot see an adjusting screw.  Do you have to remove the flywheel theft some new points and condenser?




I don't think the flywheel was removed during the service.  See pic below, looks too cruddy to have been recently removed and torqued up.





I am not sure where the engine number is. The documentation from vintage motor scooter club states VNL3M*86803.
It's a USA P125 X