Px125 problem- HELP!

forgive my ignorance but im a novice and if anyone can help id be eternally grateful.
i bought a (reasonably reconditioned)1982 px125e about a year ago and only usually run it at weekends and up until now have experienced no problems UNTIL last week that is! whilst out on an afternoon run cruising in fourth gear at around 45mph she started to lose power until she would only do 5mph max at full throttle in first gear (and even then only in spurts, the bike now seeming to want to die completely!)
managing somehow (very slowly) to get it home i proceeded to clean out the carb thinking perhaps there was a blockage/dirt in there somwhere, i also replaced the spark plug and i even took out the petrol tank and cleaned that out too just for good measure BUT STILL NO CHANGE!
i get the feeling that there is maybe a simple answer to this problem but because im a novice and therefore stupid ive overlooked this. can anyone help??

I would suggest perhaps checking your piston rings it sounds as if they might have cracked. That could be your simple answer. Just strip down the top end and there are two metal rings all the way around the top of the piston, there should only be about a 1-1.5 cm gap in them, if it is bigger or they fall apart as soon as you take off the barrel then that is your problem, that is definately what it sounds like to me.[:look:] [:shock2:] [:smokin:] [:bounce:] [:drink:] [:dance1:]

RIGHT! good news and bad news folks, i took the scooter to a mechanic yesterday and he listened to it and said it was definetly the carb and to call back later and he would have it fixed (he set jets and float etc maybe even pumped her) and as good as his word he did fix her, she was once again running smooth and sounded good SOOOOOOOOOOO whats the bad news i hear you ask? well on the way home things were going well but once i got her up to her a comfortable cruising speed (about 45/50 mph) the engine cut out as if someone had pulled the plug on her and the back wheel locked (she was in 4th gear) the scooter then screeched and swerved and snaked a little (scary as f**k!) until i pulled the clutch in. when i let the clutch out (she was still moving) she started again (just like a push start) and away she went again happy as larry!!! but once again when i got her up to a faster speed about a mile down the road she done the same thing again, fortunately i was waiting for this and clutched her a lot earlier and so it wasnt just as hairy an experience the second time round!! i kept her at around 30mph all the way home and she was fine. i think there was two faults wrong with her 1= the carb HAD collected dirt somewhere and 2= this has to be an electrical fault now, doesnt it???
oh and frustrating isnt the fing word mate!!! lol

Alright Mac to check out the damage yourself remove your cylinder head and remove the four studs from your engine casing this can be done by putting two of the 13mm nuts on the stud tighten together and use the buttom one to unskrew the stud when you have all four studs out the barrel can be removed to reveal the piston if there are any scuff marks on it rub it down with wet and dry to remove surplus alloy and with a hacksaw make an x on the nip mark dont forget to check the barrel for alloy deposits these can also be rubbed down as long as there is no damage to the internals.I know this all sounds very daunting when you first start thinking about it but beleive me its a peice of cake realy .Ycould also go back to the shop and try getting them to pick it up and do the work for you as it sounds like it was there fault with the air/petrol mix being rong .good luck m8

what kind of oil you use dylan? i definetly should improve my oil choice thats for sure as i have been mostly using the crap two stroke stuff you were talking about, the garage did say that i should be using better stuff, what brand do you recommend then?

Take your fly wheel off and check your crankshaft main oil seal. Easily replaced if this is the problem.

thanks everyone for the help but still no joy! think shes going in to the shop! the only other thing i have noticed is that when i start her up she revs extremely high for a few seconds before starting to die down where upon i have to return her to full throtle to keep her alive, does this make it any clearer for any of you. i spoke to a mechanic and he said it has to be a carb problem and that i probably have`nt set the jets or floated the needle properly again after cleaning out the carb. would this also be possible?
?

Hi Mc i`m going to go with the majority vote on this one as i have also been there but with my T5.It heat seized horrendously after i neglected to set my mixture properly then didnt bleed the autolube through so it all went arse up.Shops may very well do a decent job but get yourself into a club(must be one nearby)and start hanging with some scooterists,they are the best in the world and will probably sort you out for nothing.Its a learning curve bud.Keep the faith.[:dance3:] [:drink:] [:drink:] [:drink:]

Scooterraider is right Mac get pally with some lads from a club theres always some one who has a wealth of experience and a few beers as payment is always better than paying shop prices mate. Where r u from mac
[:dance1:]

im in county antrim, northern ireland mate! once again thanks to everyone who has tried to help here. i think ill keep her to the standard set up, not looking for optimum engine performance, just like posing on my scooter (not nearly as cool looking when you have to push the f**king thing down the road, but there you go!)
shes still in the shop and probably wont be ready until mid-week, is there anything else i should ask them to check? because i`m still not sure what the initial fault was, or was it an engine seizure from the start?

Hello,

please check you gear box oil and when there is a smell of petrol than you have blown your drive side oil seal. Maybe this will be your problem!

Good luck,

Markus[:bounce:] [:bounce:] [:bounce:]

Oh Fk! if it was a soft seize then there shouldnt have been too much damage done to the engine??? that evening after i collected her at the shop i filled her up and the mix in her wasnt too lean so i guess this is something to do with the mechanic. after the two alleged „seizes“ i rode her home quite smoothly at 30mph for another 5 miles or so and she never hinted at seizing again, i always thought once the engine seized that was it? this whole fking thing is confusing/frustrating the hell out of me! don`t feel all that confident riding it back to the shop i can tell you that, will have to get a trailer???

thanks graham! think i`ll try the shop first as i think this could have been of their doing.

its ok mate do what i did buy a bit at a time and collect it together it seems to cost less over time still my t5 is better

lost boys s.c.

I have had the exact problem with my t5 it definitly sounds like one of your oil seals has popped are you having to rev the balls out of your bike so it doesnt stall? i did and it was my clutch side oil seal hope this is a help frustrating isnt it[:angry:] [:angry:] [:angry:]

you see graham sitting stranded in the high street is where the full face helmut truly comes into its own! you keep it on so nobody knows who you are so you dont really give a flying **** therefore avoiding any twat like feelings!!! [:smile:] when you say the flywheel seal, youre talking about the mail oilseal in the gearbox? and what the hell will pinking sound like?? cheers pal!

Sorry ld i was being a tad sarky.Im only jealous cos i want a lammy but the price for anything decent(GP200)is F****** ridiculous,Ill just have to keep saving.[:dance3:] [:drink:] [:drink:] [:drink:]

get your ignition checked …

sorry, that should have said CAN`T smell fuel.

thats exactly what she was doing mark revving up like crazy and then dying.
Graham/Dirk the shop has taken her apart and there are scorings and marks on the barrel and the rings are worse, they say i need to order a new piston kit, fair enough, but whats still bothering me is what do i need them to do to her to stop her from doing the exact same thing again (seizure)as soon as i open her up to 50mph again, in other words why did it seize and what do i need to tell them to do, is it the whole air/petrol control? or is this related to the oil seal in the gear box? the shop has a good reputation but would`nt be specialists when it comes to a 1982 vespa PX125E !!!