Those LC4s came with either a Quiksilver (Edelbrock) or a Dell'Orto carb, I think in 1999 they went to the Mikuni BST-40.
All of those carbs above were vacuum or constant velocity carbs. Their slide are not directly connected to the throttle.
The Sudco you have is an after market "pumper" carb. Probably a Keihin FCR.
So someone wanted more throttle response that a CV carb can produce, and paid some bucks to upgrade.
Those Sudco's run around $600 and up.
If you want to downgrade back to a CV, I've got a Mikuni BST-40 I rather not have.....
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2011 Husaberg TE 300
2002 640 LC4e
Past Rides
'03 KTM 450 EXC (SOLD)
'01 Honda XR650R (SOLD)
'98 Honda XR600R (SOLD)
'95 KTM 620 RXC (SOLD)
'88 Yamaha TT600 (SOLD)
'86 Yamaha XT 350 (SOLD)
'84 Yamaha IT465 (STOLEN)
'83 Kawasaki KDX 450 (SOLD)
'83 Honda CB1000 Custom (SOLD)
'82 Kawasaki KDX 400 (SOLD)
'77 Yamaha DT200 (SOLD)
'70 Honda CT70 (SOLD)
