Scooterotica

Hi I'm running tv200 with taff/speed exhaust just wondering what's the best size carb to run ?

What state of tune is the cylinder?

How does it run now?

What are you hoping to gain / achieve?

If it's standard then you could probably just upjet the standard one.

Using the SH2/22 (Scootopia or fettled Jetex) such as the GP used might give a slight boost as it's a slightly more modern (late 60s compared to early 60s for the SH1) design.

If you're not to bothered about originality then some like a PHBL25 would also give a useful boost and can still be run through the airbox.

Just bear in mind that any bigger carb can come with a sharp decrease in fuel economy for very little gain in usable power. Back in the 80s the first thing you did was slap on an 30+mm Amal and a fresco and claim it went fast as fook. The likelihood was that it made more noise, spat all the petrol up your leg and really didn't go much better.

It's running on a standard carb now, but can't get it to tick over, idle scene is not hitting the plate to adjust

Buy another secondhand SH1/20. Strip, clean and use all best parts. In standard tune, not really much to be gained other than slightly more induction roar and slightly worse fuel economy.

bend the plate/throttle stop so it touches sooner pliers are your friend