Float needle BGM PRO Viton® for Dell`Orto
carburettors The float needle controls the flow of petrol into the carburettor. If the float needle is defective, the carburettor overflows and the petrol drips onto the ground and/or into the engine. A badly starting and smoking engine is often the result.
If the carburettor is revised it is therefore advisable to change the float needle as well. Unfortunately it is not included in most carburettor gasket sets, so you should still buy it separately.
SPRING-LOADED OR UNSPRUNG?
A spring-loaded float needle is the modern successor of the unsprung version and can replace it 1:1. The spring serves to protect the rubber tip from too much pressure and buffers too strong impacts of the float, e.g. with bumps, like a shock absorber. On many, supposedly non-adjustable engines, the mere installation of a spring-loaded float needle helps to tune it well. The additional buffer makes the float level much more stable, independent of the engine`s own vibrations.
TRIANGULAR OR SQUARE?
Dell`orto uses as a rough distinction two different shapes of float needle types; triangular and square. The square type is available in two different sizes: 4.5mm and 5.2mm
Triangular: Dell`Orto SHB, PHVA, PHBN, PHBG, FHBB, UB, MA18, MB A 20-24
Square 4.5mm: Dell`Orto SI20, SI24/24E, SI26/26, SH, PHBH, PHBL, VHB, MA BS5/BS7, MB B20-24
Square 5.2mm: Dell`Orto SI24/24H, SI26/26H, VHSA,VHSB
TIP: For a perfect result the float needle seat in the carburetor should be cleaned. To do this, insert a cotton swab into the hole of the float needle and turn it back and forth with gentle pressure. To clean the whole carburettor, you can use brake cleaner.
KNOWLEDGE: The most common reason for a defective float needle is wear/age of the sealing rubber tip. For this reason, the BGM PRO float needles are made of resistant Viton®.
