Vespa ET4 125cc 2001 Stumped

[milly]

First the history.
Months ago when purchased would not rev above about 2000 revs and spluttered and farted.
Changed carb for new still same.
Changed immobilizer for a secondhand bypass immobilizer all fine and dandy.

Next event ( some months later with no problems ) pulled into garage put scooter on ramp and a week later changed belt and rollers,

Tried to start ,turned over no spark. Put original immobilizer unit in and fired up but still sputtering which was expected.
Checked wiring best I could no problems noticed.

Next step new plug and coil still the same tickover fine but spluttered on reving.

Got bored one day when had spare moment and tried the old bypass immobilizer on and working but still same symptoms as before.

Today new bypass immobilizer and still sputtering and farting.

So where to go next could I have distributed something doing belt and rollers, I have checked the earth cable from belt casing to chassis is ok.
I have a good wiring loom arrived so if I cant think of something simple I have missed that will be the next job.
Anyone else experience this before.

[pinkscoot]

milly I was having problems with the connector on the CDI. It drove me nuts until I found that was the problem.

[milly]

Sept 12, 2021 8:06:50 GMT -5 pinkscoot said:

milly I was having problems with the connector on the CDI. It drove me nuts until I found that was the problem.

I shall go through it again pinkscoot to see if the connector block has any problems. Just seems odd to not function after doing belt and rollers which at other of scooter.

[milly]

Well gone through again hopefully carb. By the time I have started it done a few hundred yards starts sputtering presume after choke circuit has switched off and running on full throttle not enough fuel.
Carb cleaning done. We will see tomorrow after trying to find out problem with Ducati engine on a motorcycle.