Modern Vespa

hi there I was out riding last night on my px 210 and suddenly lost power like it had ran out of fuel . I could not restart it and will not start now , I have checked a few things , I have half tank of petrol , which is getting to the carb and into the cylinder , good compression , and a good spark I took the head off and piston and barrel seem ok no scoring etc . any help or suggestions please

I am not makin fun ....did you leave the fuel selector in the off position (probably not).....When you say good spark \I assume that you are referring to the fact that it sparks against metal. This can be done by taking the plug out of the cylinder head and reconnecting to the lead wire touch metal and kick over very slightly...

hi yes fuel tap open and I tried plug against engine whilst I kicked over but refuses to start

ok good now follow the spark plug lead wire to the cdi box and ensure it is totally screwed in. Also ensure that your connections at the cdi box are pushed in securely. This has happened to me.

ok thanks will try that

I'm gonna say if you have fuel (and its getting to the carb) and you have a good spark....then I say thing is to see if fuel is getting to the cylinder.

Turn fuel on-ignition off-kick with full throttle a few times-pull plug and see if its wet.

If its dry than you are not getting fuel from carb to cylinder.

Dirty/clogged/blocked jets

All the above information is great.
If you know anyone with the same bike, swap out CDI's and see what happens.
I fried mine once, was still able to get it to start up after 15 minutes though.
You may also want to check to see all your wires are connected up in the headset.

Not saying that this is your problem, but I had a similar problem on my P2 a few years ago whilst in the middle of nowhere touring around France / Spain.
In my case I could get the scoot going by bump starting it whilst running like a lunatic & keeping the revs high.

I cleaned the jets out a number of times to no avail. What it turned out to be was a spec of grit that was inside the carb body itself (don't know how it got there). I had to suck it out using one of my daughter's "scoobys" (long thin plastic tube like a mini straw.

Just food for thought !