Hi guys, I can't start my 50cc. it all happend when i replaced my piston. so first off i would like someone to confirm i changed it correctly if they can. i sized the piston rings up with the barrel ensuring the ring is a tight fit. when i installed the piston i ensured all bearings etc where ok, I then made sure the arrow on the piston pointed towards th exhaust out let. if you think i am missing anything or that i have done anything wrong let me know. i am at a complete loss. i removed the exhaust to ensure petrol is coming out of the out let. which it is i put my finger in the spark plug hole to check compression. which seems ok i held the spark plug by the barrel to check spark and it seems ok. i replaced the spark plug which made no difference. i hve charged the battery. with no difference. i have took the carb out and cleaned it out. al jets are clear and the diphram etc seem ok. i have replaced all the gaskets.. twice and ensured a good seal. i have changed the petrol for new perol and ensured pipes are all flowing wel. i hve used starting fluid. i can feel pressure coming out of the exhaust tip so there is no blockage there. no results from all of this so i am guessing i either have een issued the wrong piston or i am installing it wrong. FYI this is the piston i brought. http://www.ebay.co.uk/itm/Piaggio-N...=280773971356&ps=63&clkid=6240907119225461176 Please help if you can. thanks guys. :-D
yeh only the piston and rings standard barrel. The piston stataes it is a replacement for the standard piston. is this not the case ? thanks for the reply
i asked because i think you cant just fit different piston than the barrel is.. i mean piaggio barrel then piaggio piston and so on...that could be the problem mate!
Hi guys sorry i am only just getting back to the responses. I changed piston due to loss of power, i guessed due to lack of compression. turned out the guy who had the scooter before me had it bored out, poor job so piston fitted perfect in the bottom where i spaced it but at the top it was well out. i have brought a new cylender and piston (standard) and it now starts but i have annother problem now, the scooter starts fine seems as if it will run perfectly. ticks over abosolutely fine. when i put coolant in it goes straght through and withing seconds the scooter is spluttering then cuts out. if i carry on kicking it water comes out of the exhause. when i completely emptied the water and started it water flew out the exhaust when it eventually started. i thought maybe the gasket had gone on the top of the cylender head. replace all gaskets on this but still same issues, i am sealing with a liquid gasket. any suggestions ?
Does it actually leak or just come out the exhaust? What happens if you put a small bit in does it change the engine speed or smoke more ect? Id say it was gasket or head related but you said you replaced them all so
are u using a gasket as well as sealer if not there is your problrm ...ditch the sealer and just buy a gasket
yeh i am using a gasket under the sealer. if i put a little water in, the engine speed slows and if anything there is less smoke than normal. and no it doent leak just comes out of the exhaust. but i took the exhaust off and emptied the water out and there was a lot of water in there. i am going to swap the o ring again and see if it is just that. fingers crossed. if you think of anything else let me know.
Not sure what you've done but sounds like coolant is somehow getting into the cylinder. Most likely through the head. Sorry I cant help more but if you replaced the gaskets ect and its all put together properly I dont know what else it could be
thanks mate well ill give changing the gaskets a go and let you know how i get on. thanks for the help appreciate it!
IMO take off the cylinder and start from scratch with new gaskets id be suprised if it still happens. I think this is one of those annoying odd problems that you will only know the answer to if its happened to you lol.
i rekon the gasket has sliped out of the little notch and been squashed against the cylinder did it to me ..its ovb a gasket
You might find that the bore has egged, the rings will never seal properly, did you use a glaze breaker on the bore before you fitted the new piston and rings?
