Carburettor

Mikuni Super BN needle and arm spring

4 rows across 5 columns, read from 2 named sources, listed in full below. All 20 cells hold a recorded value. It is indexed under 5 engine families, named below; the rows can cover more machines than those.

Only true under these conditions. Three things the manual says that the table cannot. The 32 lbs figure is given as approximate; the other three are stated flat, and that distinction is Mikuni's. Mikuni also warns specifically against defaulting to a 2.3 or 2.5 needle valve, which it says many tuners do, and recommends the smallest needle that gives the correct pop-off for your engine, noting a 1.5 needle already flows the maximum the Super BN can pump. And pop-off is measured, not looked up: pressurise the fuel inlet with the return plugged and test three times. These are kit contents, so they tell you what a combination produces, not what your engine wants.

Indexed under: 650, 701, 750, 760, 800sxr

Where these figures came from

Confidence in these figures: High.

• Mikuni Super BN Owner's Manual, page 19, Mikuni American Corporation
• Mikuni Carburetor Rebuild Kit Master Application Chart, revised 17 September 2024

Cite this page

“Mikuni Super BN needle and arm spring”, BaddJet archive, https://baddjetarchive.com/tech/specs/mikuni-sbn-needle-spring-popoff/

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