Skip to content
View in the app

A better way to browse. Learn more.

Trials Central

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Dellorto "U" or "S" Idle Jet?

Featured Replies

Hi All,

Just fitting a Dellorto VHST carb to my bike and need to play with the jets a bit.

So with the Idle (Pilot) Jet ... does anyone know the difference between the "S" jets and the "U" jets?

Best balance.

Neo

Hi All,

Just fitting a Dellorto VHST carb to my bike and need to play with the jets a bit.

So with the Idle (Pilot) Jet ... does anyone know the difference between the "S" jets and the "U" jets?

Best balance.

Neo

Try this linkey,My link

Answer, NO!

Edited by copemech

  • Author

Yes that's good Cope but seeing as both jets look almost identical (scroll down on this page) and they are both specified as VHST spare parts I'm trying to understand why I would chose one over the other.... Might be a 2T of 4T setup thing? <_<

Any help is greatly appreciated.

Best of balance.

Neo

Claudio the difference is in the side holes, the S jets have the small side holes the U's are substantially larger. On the Scorpa four bangers running that carby it made a substantial difference to the slow running just changing between U and S for the same pilot jet size.

  • Author

Hi Paul,

Thanks for this...I'd forgotten that the Scorpa 4T uses a VHST.

The U Jets appeared to have larger side holes in the photos but I wasn't completely sure on that.

So just to clarify do you think the U Jets are for a 4T engine?...or are they just to raise the tick-over on any engine?

Do you stock the range of VHST Dellorto jets and other VHST parts?...

I also think I need a "VHSB/A Atomiser bush DQ / DP - 7mm" ... but need to confirm if this will fit the VHST?

Please drop me an email if you can supply any of this?

Best of balance.

Neo

Edited by Neo

  • Author

Wow this is crazy. I read that the VHST has been fitted to Trials bikes as far back as 2004 yet know one seem to know much about them.... Including some Dellorto suppliers.

Can someone please prove me wrong and enlighten me? :blush:

Best of balance.

Neo

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.