One of the important systems of motorcycles is the carburetor. He is responsible for the correct operation of the vehicle, its stability and durability. The functionality of a motorcycle or scooter largely depends on the design features of the carburetor. Therefore, the owners of the presented vehicles evaluate the design features and operating principle of this device.
Often, when creating domestic brands of motorcycles, mopeds and even snowmobiles, the manufacturer installs a K-65 carburetor in the system. You can adjust it yourself if necessary. The setting will allow the engine to start simply and easily, its operation will be stable and smooth. The fuel mixture will consist of the correct proportion of components.
general characteristics
The K-65 type device was created on the basis of the K-62 carburetor. The previous model had a number of shortcomings. Because of this, frequent breakdowns occurred in the system. The designers took into account all the shortcomings. They have developed a completely new design that is more durable and reliable.
The K-65 carburetor is installed on IZH Planet 5, Ural, Minsk, Buran snowmobile, etc. This is one of the most popular types of devices presented. Its adjustment is not very difficult. In case of uneven engine operation or incorrect proportions when preparing the fuel mixture, you must perform the procedure yourself.
The technology for carburetors of various brands of motorcycles and scooters is produced according to an identical scheme. To ensure stable, long-term operation of the motor, you will need to read the step-by-step instructions for this process.
How to properly adjust a motorcycle carburetor Minsk
Published May 24, 2018
We adjust the carburetor in Minsk. Our goal: to achieve maximum engine response. That is, when the throttle is opened sharply, the engine speed should increase with minimal delay. The adjustment is carried out using two parameters: ignition timing and mixture quality. At the same time, we need to remember that if the engine stalls when the throttle is opened sharply, we either have early ignition or poor timing. If it starts to pick up speed slowly, then either the ignition is too late or the mixture is too rich.
hello, it was a waste of time to cut the skirt (it disrupted the phases) in the video you can hear the dips because of the piston: the mixture flies out into the return line
noticeable failures in engine operation
hello, I changed the piston and cylinder, the motorcycle started but it was difficult, it started with the throttle half open and after starting it works a little, you open the gas on the choke and it stalls, Pacco carburetor
Hello, where the fuck did you get such a fucking arrow?
Please tell me why I’m just gasping like crazy
My Minsk has trouble starting. If it starts, it starts to stall (lack of fuel), and when you give full throttle it starts working again for a few seconds.
I don't understand about the crankshaft? Why can't you gas on the spot? Is it possible on the go?
hi, I bought a Minsk (for fishing, etc.), and immediately ran into a problem. The clutch works very tight, not even tight, but rather hard, the cable fastening is already bent))) and the range of settings for the clutch itself is small. Please tell me where to look and how to solve it. Thank you in advance
why Minsk can't go uphill. At idle it works well and drives briskly downhill, but when it starts going uphill it loses speed and almost stalls. Why tell me?
please tell me there is a Minsk for adjusting the ignition does not respond to start and immediately stalls after replacing the piston with the brakes it started and drove well after an hour it no longer got stuck! What could it be?
It starts to choke at high and low speeds at medium speeds, it seems to be working fine, but it’s not working properly, your piston probably needs 3 or 4 repairs, this is not good for Minsk, on this engine, after a bad rating, it’s better to put a new liner in, and then with these settings everything will work almost perfect
Thanks for the help! And I also have a K-62 carburetor, that’s why thank you)
This is the problem Minsk 125 stalls at medium and high speeds, as if the carburetor is choking. Should I look?
Hello! How long should the top screw be turned, near the throttle?
Kherovo is gaining momentum
service your motorcycle properly first!
Design
The K-65 carburetor of the Ural, IZH, Minsk, etc. motorcycles is characterized by a certain design. The system maintains a constant level of fuel in the combustion chamber. The fuel mixture reaches the fuel valve through the fitting. The shut-off valve has an elastic washer. The valve is connected to plastic floats. They are connected to each other. The floats can rotate.
When the fuel level rises, the excess will be drained through the drain hole. When heated, pressure may increase. To reset its excess, the design provides an unbalancing channel.
The metering device includes a sprayer, a fuel nozzle, a throttle needle, and an air channel. The first of these components is secured with a washer. It is located under the fuel supply pipe. This hose is one of the main components of the idle air system. It also includes an air channel, fuel mixture adjustment screws, and a transition hole.
Assembly features of the K65k carburetor
The K65k carburetor was produced back in the Soviet period. This can be judged by the cast body and internal parts.
Assembly of the structure consists of the following steps:
- The spray chamber is installed. It can only be fixed in a certain position. The body has a square-shaped protrusion. The nozzle groove should fit into the protruding part of the body. Now take the atomizer itself, the diameter of which is 2.63 mm. Looks around. It is purged with air and installed in the chamber.
- Then install the main fuel jet with a flow rate of 220 ml/min, an idle tube that passes 50 ml/min, and a lock washer, which has the same dimensions for all modifications of carburetors in this series.
- A fuel system is installed to control the fuel level. It consists of a needle and a two-chamber float. If all parts are without flaws, the carburetor is turned over and placed on the plane of the table. The needle is inserted into the bronze part of the float, which is fixed on the axis.
- The cover located at the bottom is being installed. A gasket is placed, and the entire structure is securely fixed with bolts. Tightening proceeds evenly to prevent the gasket from skewing.
- The starting device is installed and the mixture quality screw is screwed in.
- The top cover is assembled. A screw is screwed in to regulate the amount of mixture. A guide for the cable is also installed.
- The throttle valve together with the top cover is fixed to the K65k carburetor and tightened with bolts.
Despite the complex structure of this type of unit, knowing its technical characteristics, it is realistic to carry out the adjustment with your own hands. The main thing is to adjust the location of the float so that there is no overflow of fuel. After this, adjust the quantity and quality of fuel supply. Then, after starting and warming up, check the stability of the engine.
System operation
When adjusting the K-65 carburetor on Minsk, Ural, etc., it is necessary to understand the operating principle of the entire system. Its design has been discussed in detail above. The fuel is in the tank. From the float chamber it enters the sprayer through the main jet. This process occurs under the influence of rarefaction.
The fuel rises along the gap between the throttle needle and the nozzle. At the outlet, gasoline is mixed with air, which enters through the channel of the atomizer body. Engine operation is controlled by the throttle needle. It can be installed in one of the five positions provided.
At idle, the fuel mixture exits only through a special hole. As the speed increases, the vacuum increases. In the area of the next hole, the fuel mixture also exits. As the engine speed increases, the flow of fuel into the system increases.
General recommendations
When considering how to set up a K-65 carburetor, it is necessary to take into account a number of general recommendations. They must be performed before the process. All setup work must be carried out in accordance with the manufacturer's instructions. For owners of the presented vehicles who do not have experience in making adjustments, it is recommended that before starting work they carefully study all the requirements of the device creators.
The carburetor must be in good working order. If there is any abnormality in its system operation, it is necessary to carry out system maintenance.
If necessary, the system will need to be thoroughly cleaned. All consumables are replaced with new seals. The air filter must be clean. If necessary, it must be washed. In some cases it will need to be completely replaced.
When adjusting the carburetor, the engine must be warm. To do this, you can drive several kilometers along the highway. Only after this can you begin the procedure described below.
Which carburetor can be installed instead of the original one and why?
Today, thanks to the influx of Chinese spare parts in our country, the question of choosing an alternative carburetor for a scooter disappears by itself. PZ 26-27 carburetors from Chinese engines with a volume of 110-150 cm3 will fit well on the Ant scooter, but only with replacement of the jets (main and idle). You will also have to make a flange to attach the carburetor to the engine cylinder. At the bottom of the carburetor there is a recess with a drain hose that can touch the clutch release lever.
To install the carburetor, you will need to warm it up and bend it to the side, taking into account the squeeze. If this option does not suit you, you can simply make a longer pipe (see figure). Then the lever will turn freely without touching the carburetor. In addition, you will need to select a pipe for the air filter.
This is what a PZ 27 carburetor installed on an Ant scooter looks like instead of the original K65G
Fits into place like a native one
An accelerator pump comes as a bonus to the PZ 27 carburetor. Of course, it will be of little use on a motor scooter, so you don’t have to bother with installing an additional cable.
Carburetors with a large diffuser diameter PZ 30 or Jikov from the Java 638 motorcycle, despite laudatory reviews on the Internet, are unsuitable for installation on scooters. Carburetors with a large diffuser diameter should be installed only on forced high-speed engines. When installing such a carburetor on a standard engine, even with the selection of the necessary jets, you are unlikely to be able to set up a stable idle speed.
Setup procedure
Setting up the K-65 carburetor in various vehicles is done using a certain technology. Stable, smooth operation of the engine, fuel consumption, and engine durability depend on the correct execution of all stages of the process. Therefore, this process must be approached responsibly.
First of all, the correct proportion of the fuel mixture is adjusted. To do this, first measure the gasoline level in the float chamber. If there are abnormalities in this system, the mixture may be too lean or too rich. If the ratio of air to gasoline is not maintained correctly, problems will develop in many systems over time.
Next, you need to configure other carburetor devices. The main dosing system is being adjusted. The driver must pay attention to the trigger mechanism. The engine speed is adjusted at idle speed. By consistently performing these actions, you can achieve stable, high-quality operation of all motorcycle systems.
Adjusting the quality of the mixture in operation
Adjustment of the K 65 carburetor under operating conditions is carried out by moving the metering needle relative to the lock. This should be done in a certain order.
The dosing needle is set to the middle position. To lean the mixture, the lock moves upward. At the same time, the gap between the dispenser cone and the wall of the atomizer becomes smaller.
Moving the lock down will result in a richer fuel mixture.
The color of the spark plug electrode insulation will indicate the need for adjustment. You should pay attention to it after 30 km. Under normal operating conditions, its whitish color indicates a poor mixture. A dark brown insulator with traces of soot indicates the need to lean the mixture.
Fuel level
Adjusting the K-65 carburetor begins with measuring the amount of gasoline in the tank of the float section. To do this, you will need to prepare a certain list of tools. Almost every home craftsman has them. The tool will be required during the process of dismantling the carburetor.
When the device is removed from the slots, you will need to remove the cover from it. It covers the float chamber. Next you need to take a ruler. The float has a special tongue. It needs to be unbent and bent to make adjustments. Due to this, the fuel level in the chamber will change.
You will need to place a ruler on the connector plane. Next, the tongue must be adjusted correctly. The strip on the float should be at 13 mm. The deviation is ±1.5 mm. The floats themselves must be level. The adjustment must be made very precisely. The operation of the carburetor depends on this.
Setting up on the Ural
Adjusting the K-65 carburetor on the Ural motorcycle has several distinctive features. The entire unit does not need to be removed from the vehicle. Dismantling this type of vehicle can be very difficult. Therefore, the procedure is carried out directly on the motorcycle.
To adjust the gasoline level in the float chamber, you will need to find a similar element from another similar motorcycle. The vehicle is firmly installed on the stand. The gas valve gradually opens. Fuel flows into the carburetor. The hose is disconnected and the gas tap is closed.
The bottom cover filled with fuel is removed. By comparing the fuel level, a conclusion is made about the need for adjustment. The tongue can be bent.
Carburetor synchronization
After tuning, the K 65 carburetor (Ural) must be synchronized. This can be conveniently done using a tachometer. In the absence of such equipment, synchronization can be performed using the speedometer.
To do this, place the motorcycle on a stand and start the engine. 4th gear is set. Remove the cap from one of the spark plugs and adjust the speedometer reading to 50 km/h. The gas handle is fixed with a bolt.
One cylinder turns on and the other turns off. The length of the cables is adjusted using fittings. At the same time, they achieve the same speedometer reading.
When removed, the spark plug cap must be grounded and shorted to the ground of the motorcycle. In this way you can adjust the Ural carburetor.
Candles
The K-65 carburetor for IZH, Ural and other brands of motorcycles must have the corresponding appearance of the spark plugs. A visual inspection is sufficient. If a new carburetor is installed, you will need to drive a motorcycle or scooter on the highway for about 30 km. Engine speed should be high or medium.
After this, you can put the vehicle in the garage and begin inspecting the spark plugs. Soot should not appear on their surface. If this happens, there is not enough air in the mixture. Such fuel is called rich. The spark plugs will need to be cleaned before tuning.
In some cases, the surface of the candles turns white. This picture is observed when the system prepares a mixture that is too lean. There is too much air in it. The normal color of candles should remain in the range of yellow to reddish-orange. In this case, no configuration is required.
Throttle needle
When studying the technology of how to adjust the K-65 carburetor, you need to pay attention to the shut-off valve. This is the throttle needle. If it does not cover the channel hermetically, the level of gasoline in the fuel mixture may be higher than the required level.
The throttle needle has several channels on its surface. The latch moves along them. In this case, it is possible to adjust the composition of the fuel mixture within small limits. The gasoline consumption of motor vehicles depends on this indicator. If you need to add more air to the mixture, you need to lower the needle. And vice versa.
When dismantling the float chamber, it is necessary to monitor the position of the throttle needle. If you move it carelessly, it may fall out. There is no way to lose this structural element. Therefore, the procedure is carried out very carefully. If the rubber elements of the throttle system are worn out, they must be replaced. The needle should move easily along the saddle.
Idling
The K-65 carburetor is adjusted at idle. The engine must be well warmed up. At idle, the engine should run stably. Use a screwdriver to adjust the horizontal screw. To do this, turn it in the appropriate direction until speed stability is established.
After this, you can tighten the quality screw. A screwdriver is also used for this. When rotating the screw, you must listen to the operation of the motor. The number of revolutions at the maximum level should be stable.
Next, by opening and closing the throttle, the correct idle speed adjustment is checked. If the gas is applied suddenly, the engine will stall if the adjustment was carried out incorrectly. If this happens, the mixture will need to be enriched. At the moment of abrupt closure of the damper, stopping the engine indicates a lack of air in the mixture. The screw is loosened slightly.
Dosage system
The K-65 carburetor is adjusted especially carefully in the area of the metering needle. Its position must be carefully adjusted. The engine must be well warmed up. If it has already cooled down, you need to ride the motorcycle for some time on the highway.
On a straight section of the route, you can evaluate the engine's performance. If turning the throttle does not have sufficient effect, you will need to raise the needle. This will lead to an increase in gasoline in the fuel mixture. If after the next trip carbon deposits appear on the spark plugs, you will need to lower the throttle needle one notch.
This approach will ensure stable operation of the engine at medium speeds. This is the most frequently used mode when operating motorcycles. The maximum speed allows you to adjust the measurement of the jet cross-section. When the throttle is turned all the way, it will ensure the operation of the system.
Having considered what the K-65 carburetor is, as well as its structure, you can adjust it in accordance with all the manufacturer’s requirements.
Two carburetors on IZ Jupiter
Among all the various modifications for the two-cylinder Izh, the installation of two carburetors on the motorcycle engine stands out. One for each cylinder. This is done in hopes of increasing engine power by improving the filling of each cylinder. The power does increase, but at most by a couple of horses.
In addition to modifying the intake ports, it will be necessary to install a reed valve on each cylinder. If this is not done, then when the engine is running, the mixture will spit back into the air filter and the filling will deteriorate. It is normal for the mixture to be thrown back into the carburetor when a two-stroke engine is running. Thus, the engine “breathes”.
Therefore, on most two-stroke vehicles there is an intake resonator between the carburetor and the filter. It is a plastic box into which part of the mixture is spat out. This device is not available on Jupiters, because there is no particular need for it due to the length of the “pants” and the peculiarities of the two-cylinder engine. While one cylinder is making its stroke, the second one sucks in the mixture from the carburetor plus the part that was reflected from the skirt of the first piston.
In addition, installing a reed valve will improve cylinder filling at low and medium speeds, and fuel consumption will be slightly reduced. The Jupiter cylinder is approximately equal to the volume of 175 cm3, so the reed valves can be supplied from sunrise 3m-01 or made from a turner according to a sample. Carburetors can also be taken from Voskhod (K-62V, K-65V) or from Java 638.
In addition to installing the valves, the pistons will also need to be modified. A hole must be made on the piston skirt on the inlet side, as shown in the figure. This is necessary in order to reduce the inlet resistance necessary for the operation of the petals.
To operate two carburetors, you will need a tap with a double and a common throttle handle for both cables. These parts can be taken from the Urals or picked up from other motorcycle models.
After installing all the parts, it is necessary to configure and synchronize the carburetors. Otherwise, overheating and wear of one of the cylinders, as well as severe vibration, may occur.
