please help me fix my moped

well i spent all weekend working on the 78 puch newport, (i ordered the 70cc kit) i installed everything, new spark plug, cleaned the gas tank. i cant get the damn thing to start. there is a spark when you pedal it sounds like it wants to start, the horn works lights go on. but it doesnt turn over.

from what i can see it doesnt look like there is any fuel getting to the spark plug, when i check the plug its dry. there is fuel getting to the carb (i put in a new fuel line) i checked the piston movement and its going back to the intake manifold inlet hole.

i have no idea what could be wrong with the carb (arreche) its brand new. i've been pulling my hair out trying to think of what could be wrong. if anyone has any idea it would help me out so much.

Re: please help me fix my moped

Did you make sure to install the piston correctly? And what jet are you using?


Live to ride, Ride to work

Re: please help me fix my moped

Spray some Starter Fluid into the carb/intake (or into the spark plug hole) and see if it fires up.

If it does, everything is probably OK but the carb is not delivering fuel for some reason..

Trace fuel flow.. you say it's getting into the carb? Remove the float bowl and see if fuel is really in there.. Or, if there's a drain on the bowl, open that and see..

a "new" carb, meaning.. brand spankin' new? I doubt a new carb would have a mechanical problem but you never know.

Re: please help me fix my moped

If its not the carb it could be the line/filter/ or peticock.


Live to ride,Ride to work

Re: please help me fix my moped

the piston is installed correctly moves freely in the cylinder the way it should the head bolts are torqued to specified amount and the fuel line is clear so i can see the fuel go right up to the carb i know its getting there. when i take the carb off i can hear the gas in the bottom portion. i tried the starter fluid in the cylinder i cant tell if its making a difference because it still isn't starting. the only thing i could think of is that there is a clog in the carb somewhere. i should probably just take it apart and see what is going on although i dont see why that would happen. its brand new as in took it out of the box and attached it. thanks for the help, im just really stuck on this.


If a squirt of Starter Fluid doesn't result in some VvrrroooOOom.. , the spark plug is not sparking (or maybe there is no engine compression).

Pull the plug and ground it's base to the engine block's fins with a spring clamp. Attach the boot, crank the engine and you should see the plug tip sparking.

As far as inadequate compression, that Starter Fluid is pure ether (with a bit of lube) and should even burn in the open air without any compression at all.. So, im gonna guess you aren't getting spark.

Re: please help me fix my moped

So you're SURE the piston is rotated correctly with the arrow pointing down toward the exhaust? Okay..........if the plug's dry,it's not getting fuel, which means it may not be pulling fuel. The reed valve is in correctly? No chance you blew out a crankseal is there?

Make sure you keep pumping a little 2-stroke oil in there every once in a while until it starts. You could lose you lubrication trying to start it.

Loosen the float bowl,or float bowl drain screw and MAKE SURE you have gas in that carb......FRESH GAS. don-ohio

Re: please help me fix my moped

Yeah definally check on the reed valve and thats it on and on correctly because i installed my whole speed kit, and tried to start it up and nothing at all, couldnt start it .. ended up forgetting to put the reed valve on ! yeah that sucked .. anyway, somethings gotta be installed wrong

Re: please help me fix my moped

the arrow points to the ground? i thought it was supposed to point up towards the intake? maybe that is my problem. the instructions that came with the kit said it wouldnt need a reed valve anymore. i did the whole spark plug on the engine and it definitely sparks. i thought the piston was the same on the top and the bottom although i could be wrong. hopefully thats the problem and it will be easy to fix. thanks again guys. i will keep you updated.

Re: please help me fix my moped

Yep............that's your problem, Sprock! Get that piston in the right way. Your ports aren't lining up with the piston cut outs.

No reed valve needed? That's okay, as long as that's the way they set it up. don-ohio (:^D

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