Fuel and Carburettors
Hardi Electric Fuel Pump |
Grob 109 uses Hardi model H cat 2212.
As of Sept 04 there is no info on this model on the Hardi website.
HARDI.de electric
fuel pumps |
Zenith Carburettor
The zenith carburettor can only work properly if the float level is
correct. The setting is 16.5mm and I have made a very simple tool for getting
this right. Anybody who wants a drawing of this just email me. If you decide
to buy a tool for adjusting the main jet be aware that there are two types,
slot or hex. plus some early types that have the adjustment on the bottom
of the fuel bowl. The main jet tool helps prevent damage to the diaphram.
The correct needle for L2000 EB and L2400 EB is B5CK and the float chamber
needle and seat is 1.75. Make sure the needle and seat is brass not nylon
as is usually supplied by automotive stores.
The mixture adjustment is to compensate for slight variations in floats
and the way the needle mounts in the piston. This adjustment basically
only affects the idle mixture. If the carburettor is set up correctly a
lean mixture can be caused by leaks around a worn throttle spindle or other
air leaks. Rich mixture indicates a damaged diaphram. The oil in the dashpot
is to help richen the mixture on acceleration and should be weight 68 not
engine oil which is viscosity modified. I suppose engine oil is better
than no oil. You can test the mixture by raising and lowering the dashpot
piston while on idle - with care.
See Limbach MI 10.3 for further information.
Information courtesy John Callahan
Grob 109 balance tube between carbs
630mm long, id approx 14mm to 14.5mm
