Mikuni VM series, round slide carburetors
From OpenContent Curriculum
Mikuni round valve (slide) carburetors are a common form of fuel delivery used in the popular brands of two-cycle snowmachines. They use a system of jets, needles, and air control, which overlap in function, to provide a smooth delivery of fuel at all levels of engine function. These carburetors are quite simple and readily learned and can be easily maintained and repaired.
Special Safety Precautions should be heeded when working with carburetors:
- Gasoline is highly volatile and flammable. Carefully drain and safely dispose of any fuel contained in the carburetors. Avoid working where sparks or open flame exist.
- Compressed air and aerosols may be helpful in cleaning crevices and small openings and holes. There is often a tendency for matter to rebound when compressed gases are directed in such a way. Make sure to protect your eyes!
and in regard to the equipment...
• Mikuni Carburetors are constructed mainly of relatively soft, non-ferrous metals including zinc, aluminum, and brass. They are very functional and adequate for their intended purposes. However, one must use care, especially in working with the soft brass jets, to avoid stripping or breaking threaded parts.
The Mikuni round slide carburetors used on many snowmachines are rather simple in design, but with parts which can be rather confusing in their terminology. The picture above shows just about any part which is made to be removable and has a name. This picture is not intended to help you in any way other than to identify parts.
- Disclaimer: It should be understood that the example used in this pictorial is a salvaged carburetor. This carb was not removed from a running machine - nor would a machine likely have run with it installed. It does show some of the issues one might encounter, albeit to a greater degree than one would expect to find normally. This carburetor actually shows very little wear in spite of the crud both inside and out. It will easily function perfectly again.