The process in which a mixture of fuel with the environment (air) occurs is called carburetion, and the device that mixes these two components is called a carburetor (KB).
With it, fuel is converted into gas from a liquid medium using various working methods: spraying, blowing air particles of fuel and heating.
The combustible mixture must meet the following characteristics:
- have a vaporous state at the time of ignition;
- the composition in the cylinder should be uniform to ensure optimal performance.
It is important to regularly diagnose this device every 300 km.
Before you adjust and adjust the Mikuni carburetor on the Taiga snowmobile, it is recommended to look at the diagram and, in accordance with it, carry out preliminary work.
Carburetor Cover Removal
Follow the steps:
- Remove the intake silencer and the fuel feed pipe.
- Unscrew the cover of the first KB, pull the choke 5 from the KB device.
- Pull the cable out of the throttle and loosen the clamps of the rubberized coupling of the engine assembly responsible for supplying the mixture to the cylinders.
- Remove the KB from the motor.
Attention! Use caution when handling the throttle. Damage arising during the running-in or long-term operation can lead to “jamming” of the throttle during its closing.
Clean the assembled device with solvents. Dry with compressed air before assembly.
Attention! The KB cleaner cannot be used for the float and rubberized elements, as well as round rings. It is better to remove the parts in advance, before cleaning.
Step by step cleaning is carried out as follows:
- With the help of cleaners, they clean the KB case with jets.
- Check for debris in the filter, clean and replace if necessary.
- Check the quality of the needle type valve 16. If there is a malfunction, then the needle and valve seat must be replaced completely.
- Check the degree of wear of the throttle, if necessary, then replace it.
The idle screw (HD) 7 must be symmetrical – replace it if necessary. Check fuel in float (P) 12 and replace if damaged. The part itself also look at corrosion – it prevents free movement – replace if any problems are found.
Disassembly and assembly
Remove the screws from the plate 4 to remove the needle 3. Its place must be adjusted using the lock 2, which is inserted into one of the 5 ditches located not on the upper half of the needle. Position 1 (in the upper part) corresponds to a lean composition, which means that the needle must be lowered (the amount of fuel is small), and position 5 (at the base) – the most enriched fuel mixture.
The last character in the identification number of the location of the needle indicates the appropriate location of its lock (from its upper part).
Experts advise regulating carburetors when the running of a snowmobile Taiga ST 500D reaches 300 km. For this purpose, the owner can choose one of the most suitable options: give the transport to a paid service center or adjust the carburetor yourself. Following the instructions, any beginner will complete this task. Before adjusting, you need to familiarize yourself with the device in more detail.
How to adjust the location of the device float
An important condition for high-quality engine operation is the correct location of the float inside the KB chamber.
To verify the correct positioning (P), do the following:
- remove the chamber (P) 11 and the gasket from the carburetor;
- make sure the symmetry of the part used for mounting on the vertical plane of the float 9;
- With the carburetor, which is installed top down on a flat surface, measure the height between the surface of the body and the top of the contact foot. Hold the ruler in an upright position parallel to the axis (P) along with the center passage of the main nozzle.
To adjust the height, bend the contact paw (P) until the desired value is reached, i.e. 23.9 mm.
Installing a carburetor on a snowmobile Taiga 500CT
The process is carried out in the reverse order of removal before installing the carburetor; you need to check the quality of the body and the triple cable (designed for gas control).
A rubberized device designed to connect the ends of the intake manifold shafts to each other must be checked for damage. During the collection of the design bureau, this coupling must touch the collector cover, otherwise, the power unit may be damaged.
Install the connectors used to fasten and seal the hose connections (worm type) so that their bolts are offset. Install the gas cable in the needle retainer plate.
Note: do not overlap the hole made in the throttle while setting the needle retaining plate, this is an important condition. Thus, it is possible to provide lubrication of all rubbing surfaces of the throttle well from the ICE power system assembly. See if there is a needle seal that has plastic as the material. Damage to the power unit may occur if this circuit is not used in operation:
How to adjust Mikuni carburetor
First, adjust the KB of the Snowmobile Taiga st 500 d in advance with the engine off. Tighten the quality screw 6 and unscrew it taking into account the data specified in the manual. When you turn the screw clockwise, you need to enrich the mixture and when turning counter-clockwise, lean.
- Unscrew the control screw completely from HD 7, which should not come into contact with the throttle.
- Loosen the lock nut of the screw for adjusting the cable a little and pick up the cable backlash.
- Press the throttle control lever – the lower part of the throttle should be at a level with the top of the diffuser or no more than a millimeter lower (motor side). If necessary, adjust the throttle position by turning the screw.
Take care that the throttle does not touch the carburetor cover so that there is a gap.
Important! Clearance is a must. If the throttle touches the carburetor cover when opened, the gas cable or other elements in the drive may be damaged.
How to adjust and adjust the choke timing
Check if the throttles of the carburetor device open synchronously: remove the intake silencer, take a mirror and look into the diffusers. Then slowly squeeze the throttle control lever. With asynchronous, not simultaneous movement, adjust the position of the throttles using the triple cable screws.
Using the RPM screw, make a gap between the lower part of the throttle (on the motor side) and the 1.5 mm diffuser. (Use a suitable wire size during the installation of the free space).
Final adjustment on a running engine
It is necessary to start the engine and let it run for 3 minutes at least and 10 minutes at most. After that, adjust the RPM speed by turning the screw 7 (according to the diagram) for the engine in the clockwise direction or counterclockwise to decrease it. Now turn off the engine and check the parameters.
|Check||What should be|
|Backlash on a covering of cables of the corrector from fuel||“Closed”|
|Needle locks||Central 3rd Ditch|
|Carburetor Dosing Elements||GTZh230 (main nozzle for fuel);
ZhHH55 (jet nozzle HD). It is recommended to replace HD jets with 40. You can remove them from the VM34560 carburetor
|Arrangement of screws of quality of mix HD||To correctly configure KB VM34619 with the idle jet, it is recommended to fully tighten the screws and unscrew by 2 turns. For KB VM34619 with an HD 40 jet, unscrew the screws one revolution.|
|Mikuni carburetor fuel nozzle diameter on a Taiga 500 snowmobile||25|
Check the adjustments:
- Clean spark plugs from soot dirt, set a clearance of 0.7 mm.
- Drive 4 km without bumping, gaining 45 km / h.
- Stop the Taiga snowmobile and turn off the engine (do not leave on HD).
- Unscrew the candles and look at the color of the resulting carbon deposits.
- If the candles are dirty or there is soot, then move the locks of all the needles into the 2nd groove (top).
- Perform the necessary actions again, which are indicated in points 1 and 3.
Set the screws for the HD mixture.
Attention! No need to unscrew the screws more than 2 turns.
Check engine after adjustment
After setting the carburetor, you need to look at the efficiency of the power unit in the modes, measure the engine consumption at a speed of 50 km / h, taking into account only the 1st driver.
To get quality testimonials:
- fill the full tank with gasoline and write down all the data that the odometer shows (total distance meter);
- start the Taiga snowmobile engine and drive a few kilometers, according to the odometer readout, calculate the path (s, in kilometers);
- add gasoline using a measuring canister to the snowmobile tank, calculate the amount of fuel spent;
- using the formula gt = v / s • 100 (liters per 100 kilometers), calculate the gasoline consumption.
Recommendations from experts: if the RMZ550 engine is installed with the KOSO gas temperature measuring sensor included in the kit, you need to look at the temperature of the power unit at high speeds. The temperature can reach 745 degrees. If the indicated temperature is much higher than normal, then vent gas.
Recommendations of specialists for working with a carburetor:
- do not use solvent to wash rubber parts, as well as rings and a float, because these substances can lead to corrosion;
- flush the housing with the jets with a cleaner;
- check the filter 15 regularly and clean or replace if necessary;
Check the candles: residual fuel that does not burn when the carburetor pours fuel, stick to the electrodes, preventing the engine from starting up. To find out why overflow occurs, you need to check the shut-off valve 16. If there is a malfunction, then it is replaced with the socket. If necessary, it is recommended that you contact an authorized dealer for diagnostics and repairs.