Scooterotica

Hi my standard G.P. 200 has started stuttering & four stroking at low revs when changing gear. I'm using a standard 22mm carb. I have to drop down a gear & give loads of revs then change up. Ticks over fine & runs fine when opened up. Any ideas please

You say "started stuttering and four-stroking" Does this mean it previously ran well and this is a new thing?

When I first got the scoot 5yrs ago it started doing the same thing. I changed the dellorto atomizer for a jetex one of the same size & it seemed to cure it. Have done about 6000 miles on it with no problem but now it's back with a vengeance. It's a original 22mm dellorto carb I'm using so its it's probably a bit worn.

Could be a leaky needle/float valve. Atomisers don't wear in these carbs, to be honest.

I haven't checked the float needle yet. I changed it about 5years ago. It might just be coincidence that scoot ran fine when I changed the atomizer for a jetex one last time it played up. Seems strange its doing the same thing 6000 miles later..plug is a very dark brown.

Do a bit of research or call a decent shop to make sure you get the right one. There are two lengths possible, I think, and different tip materials.

Black one was in the carb when I bought it. I fitted a red tip one I bought from scooter restorations.

If it has happened during the recent hot weather, this could be the answer.
I don't agree with the idea a leaky float valve would cause this.

It could easily be due to the warm weather as it will run rich when the air temp goes up.

You might be right. it started yesterday when I was riding back from work. The temperature was in the 30s. Was fine when I road to work in the morning at 5am when the air was cooler