MIKUNI VM26 carburettor slide - choice of cutaway

MIKUNI offers this carburettor slide. The slide is a kind of sliding gate across the carburettor’s air passage: with the throttle closed it blocks almost all of it; with the throttle open it lifts and lets the air through.

Why change the slide?

The benefits:

• Replace a worn slide that has play and lets extra air through.
• Fine-tune pick-up just off idle: a different cutaway cures a flat spot or an over-rich mixture at the start of the throttle opening.
• Get back a throttle that moves freely and snaps shut properly.

Why choose MIKUNI?

Mikuni, founded in Japan in 1923, is known for supplying carburettors to many major Japanese manufacturers; its TMX38 is original equipment on Yamaha YZ125s and KTM 150 and 250 two-strokes: Mikuni jets, needles and slides are the original parts for these carburettors.

When should you replace this part?

A slide that is scored, worn or loose in the body, or a split diaphragm on a CV carburettor: the idle becomes unstable, the engine draws in extra air and the throttle sticks.

Specifications and fitting tips

• Manufacturer part number: VM28/56-1.5 / VM28/56-2.0

Cross-Mania tip: Fit the slide the right way round (cutaway towards the air filter), check it slides freely with no tight spots and check the throttle cable free play with the bars turned fully both ways.

Compatibility

Universal part: check the dimensions given before ordering.

Which cutaway? The cutaway is the notch at the back of the slide, on the air filter side. It sets the mixture between idle and quarter throttle: the higher the number, the leaner the mixture (less fuel). The number is stamped on the original slide; if in doubt, take the same one.