Mikuni Large Round Main Jets - 4/PK #100

Genuine Mikuni large round main jets (#100) for carbureted V-twin motorcycles, sold in a 4-pack. These jets meter fuel into the main circuit under load and are essential when re-jetting for altitude, air filters, or exhaust modifications.

Features

• 4-pack quantity
• #100 main jet size
• Genuine Mikuni manufacture
• For large-round carburetors

Specifications

• Brand: Mikuni
• Manufacturer Part #: FN100604-100
• Quantity: 4 per pack
• Jet Size: #100
• Length: 4.4 in
• Width: 2.2 in
• Height: 0.6 in
• Weight: 0.05 lbs
• Country of Origin: Japan

Fitment

Fits Harley-Davidson and Indian Motorcycle V-twin models with Mikuni large-round carburetors. Verify your carb bore size and jet style before ordering.

Frequently Asked Questions

What does a main jet do?

The main jet controls fuel flow through the main circuit when the engine is under load and above ¼ throttle. Changing jet size compensates for altitude, air filter, or exhaust changes.

How do I know if I need a #100 jet?

You'll need to test-ride and compare plug color, performance, and idle quality. Consult your carb manual or a tuning guide for your specific setup.

Will these fit my Harley or Indian?

Only if your bike runs a Mikuni large-round carburetor. Check your owner's manual or carb body for the Mikuni badge before ordering.

Why are they sold in 4-packs?

One jet per carb is typical; the 4-pack suits multi-carb setups (like a four-carb bike) or riders who stock spares.