Another 2T to get running By FACE PLANT FOR LIFE (Read 202 times)

[FACE PLANT FOR LIFE]

I'm sure I've mentioned how my brothers Vespa Piaggio Ciao doesn't run somewhere in here. And seeing how you guys got the Razz running, I am hoping you can help with this as well!

Keep in kind that this Vespa is an actual "moped" with pedals (does that violate the "Scooter"doc rules? ).

The problem with this thing is that you pedal to start it and it won't stay running. If you pedal fast enough the bike will actually fire (we can only hear it with the muffler off) as long as you keep pedaling, but the throttle has no effect, and if you stop pedaling the bike also seizes to run.

Not sure if it's a carb or motor issue. But a little bit of help on where to look would be great appreciated!

[2stroked]

While growing up I briefly owned a moped. I have no clue what it was other than puke green and scary loud! Now at one time the gasket under the intake went out and it acted like u say ur bro's does. IMO u have a sucking air leak. If u can hear it fire a little some fuel is gettong the cylinder but no idea how much. Try to cover ias much of the carb inlet as u can, then try to start it. If it still acts the same quickly pull the plig to see if it is wet. Try that & get back to us
Oh, PUT THE PIPES. BACK ON. 2T ENGINES NEED THE PIPE TO RUN RIGHT.noy using the pipe can cause more trouble than u think.

[Alleyoop]

First thing to do is check if the spark plug is firing, get the rear wheel off the ground and turn the pedals by hand and check.

If the spark plug is firing then check if the carb is getting gas. If it hasn't run for a long time you will need to take the carb off and clean it out and all its passages. The mopeds are very finicky for starting if the carbs adjustment are a little off and it does not take much.

And You must have the Muffler on otherwise you will never get it to run, 2 Strokes need back pressure.
Alleyoop

[FACE PLANT FOR LIFE]

Spark plug fires. Carb is getting gas, but the carb now has a leak in it (oh no, this is sudden). We have determined it needs a full front-end rebuild. We can see the compression escaping out of the head while trying to turn it over..

[Deleted]

out of the head as in cracked head? or have you checked the head bolts are tight?. spark plug not stripped or loose?
if its a cracked head then the fix is obvious, but the spark plug hole can be helicoiled if needed.

[FACE PLANT FOR LIFE]

It looks like a cracked head..we compression tested it yesterday and it was running at 115 PSI, which is more than enough for it to run (132 is stock in this bike)...maybe a little crack like this wouldn't allow enough compression to escape to not make it run? Because we have spark, and apparently we have compression, and we have fuel, which combusts only if the exhaust is off but won't keep firing like that. I'm thinking the exhaust is clogged..!

[2stroked]

Take some kerosene and pour it through the pipe. Just enough to see. If it doesnt come through yup, plugged. If it does, stop the other end pour in about a twenty oz bottle of cleam K1 and slosh it around. Lay it at an angle and leave it soak over night. That will take care of most of the carbon.
If tje low compression is from burnt rings or a seal it still may not start.