The 785-24001-O-4 is a brass needle jet from Mikuni’s 389 series, made to fit TM32–TM38 flat-slide carburetors. The O-4 size flows more fuel than the O-2, giving your engine a richer mid-throttle mix. It's a solid choice if your bike feels a bit lean under load and you want smoother acceleration without going too rich.
Jet Series: 389
Fits: TM32, TM34, TM36, TM38 carbs
Material: Brass
Length: About 47 mm
Head Diameter: Roughly 6.5 mm
Shaft Diameter: Around 5.2 mm