The Sunrise is a road bike. It was very popular in Soviet times, but is no longer produced. The most popular model is considered the Voskhod 3M, an engine whose repair is completely simple and completely easy to maintain. The reliable design and stability of the bike make Voskhod an excellent friend for any motorcycle enthusiast.
Since nowadays you can only buy such a motorcycle second-hand, you have to tinker with the technical part of the motorcycle. You will be very lucky if the previous owner kept the bike clean and used it according to recommendations. If not, then frequent repairs of the Voskhod engine will take up your free time.
Voskhod 3M is considered a direct competitor to the YAVA 350 motorcycle. However, Voskhod breakdowns happen an order of magnitude more often. This happens mainly due to the negligence of the owner. Failure to follow operating instructions leads to minor problems that create significant problems. A special feature of 3M is the chassis. The brake pads were equipped with a wear sensor, the shock absorbers were fitted with corrugated rubber covers , and a protective shield was installed on the front wheel. The design of the Voskhod 3M engine also changed slightly after the modification was released. Motor 3M-01 with five-channel cylinder purging and one exhaust window.
Motorcycle engine repair Voskhod
The Sunrise is a road bike.
It was very popular in Soviet times, but is no longer produced. The most popular model is considered the Voskhod 3M, an engine whose repair is completely simple and completely easy to maintain. The reliable design and stability of the bike make Voskhod an excellent friend for any motorcycle enthusiast. Since nowadays you can only buy such a motorcycle second-hand, you have to tinker with the technical part of the motorcycle. You will be very lucky if the previous owner kept the bike clean and used it according to recommendations. If not, then frequent repairs of the Voskhod engine will take up your free time.
Voskhod 3M is considered a direct competitor to the YAVA 350 motorcycle. However, Voskhod breakdowns happen an order of magnitude more often. This happens mainly due to the negligence of the owner. Failure to follow operating instructions leads to minor problems that create significant problems. A special feature of 3M is the chassis. The brake pads were equipped with a wear sensor, the shock absorbers were fitted with corrugated rubber covers , and a protective shield was installed on the front wheel.
The design of the Voskhod 3M engine also changed slightly after the modification was released. Motor 3M-01 with five-channel cylinder purging and one exhaust window.
Tuning options
Refinement of the design involves internal or external tuning. During internal modifications, the engine is rebuilt, driving parameters, suspension, and brakes are optimized. When external modifications are made, the motor vehicle is given a sporty style or it is converted into a chopper.
Features of internal tuning
Owners often rework the Voskhod-3M engine. To increase engine thrust, the factory paper air filter is replaced with foam filter elements. This helps reduce air exhaust friction. Then the jets and diffusers are polished using an abrasive material, the diameter of which affects the volume of fuel entering the engine.
To improve the fuel exhaust system, a new modernized carburetor is installed. From the existing pipe, take flanges for mounting on the cylinders, grind out aluminum bushings, and cut off the flange from the exhaust pipe. In an old carburetor, take a second flange. Using cold welding, the parts are connected.
The design is adjusted until it fits perfectly into the exhaust channels. Internal gaps are filled using epoxy glue.
Often rear adjustable shock absorbers are installed and sports tires are installed. When performing such tuning, the motorcycle becomes more aggressive and sporty.
Performing external tuning
In a sporty style
With a low seating position and a high front fork, there is a desire to modify the motorcycle in accordance with the sporty style. To do this, raise the rear shock absorbers and replace the exhaust pipe elbow. This way the exhaust pipe is level with the rear axle. Exhaust pipes with a larger diameter will improve the design and increase the traction of the bike.
External modifications can include painting, chrome plating, installation of nickel-plated arches instead of the old factory protection, installation of large rear-view mirrors, stepped seats and wheel tuning.
At the end of the tuning, a sports fairing is installed.
Chopper
When performing tuning for a chopper, shortened rear shock absorbers are cut off or purchased. Thanks to this replacement, the rear of the motorcycle will be lowered by several centimeters. The rear fork and wheel are replaced with wider ones. The angle of inclination of the front fork axis is replaced, and the cylinder covers are equipped with chrome plated cups. The same style is followed when tuning the headlights, rear lights, and dashboard.
Tuning for Cafe-bike
With such a modification, to reduce costs, they weld the rear part of the frame with their own hands, shorten the fork, trim and adjust other parts. For the steering wheel and seat, your own strength may also be sufficient. A headlight with a brake light is installed from trucks.
Most owners can carry out tuning on their own using only purchased parts due to the simplicity of the designs and the low cost of spare parts.
Engine diagram
For Voskhod motorcycles, the engine size was the same. It was 173 cm3. In general, all bikes from this manufacturer had the same single-cylinder engine with two power strokes and an air cooling system. The very small volume of the engine produced 10 horsepower and over time, modifications to the engine began to produce power of 14 hp.
If you discover a malfunction and it is related to the operation of the engine, do not put off repairs for a long time. Exacerbating the problem will result in unexpected costs. There is no need to be afraid to overhaul the engine. Not only disassembly, but also assembly of the Voskhod engine is very simple.
Before repairing, carefully inspect the motorcycle for wear or broken parts. After inspection, clean the engine from dirt. It is better to wash it thoroughly with a cleaning agent. Since the main engine problem is the crankshaft bearings, seals and gaskets, let’s consider the process of repairing them:
At the same time, be careful not to overtighten the crankshaft, otherwise it will move or bend. In this easy way you can replace bearings and gaskets in the engine. As you can see, the work does not require hard-to-find or rare tools.
What kind of breakdowns can occur in Voskhod, Minsk, Sova bikes?
And the only sure way to keep these “veterans” of the motorcycle industry on track is to timely diagnose and eliminate breakdowns, and carry out repair work using high-quality spare parts. We advise you to take a closer look at the following weak points of these motorcycles:
Although the basic equipment of the motorcycle is quite laconic, it is not without its shortcomings.
· rather weak engine, inability to accelerate over 100 km/h;
· possible slippage due to ill-conceived design of the clutch assembly;
crankshaft deflection due to poor placement of bearings;
· rigidity of factory shock absorbers;
· not too powerful brakes.
Force
To increase power on Voskhod 3M, you can do engine tuning yourself. Even simple manipulations like an air filter can increase performance.
For a stronger increase in power, you can replace the intake system. For example, install a new carburetor. Perhaps even from another motorcycle with a similar system. There is an option in which you can install two carburetors, but you will have to connect pipes to it and weld the channels, filling the cracks with epoxy liquid.
Description
Motorcycle engine Voskhod 3M single-cylinder, two-stroke with a volume of 173.7 cubic centimeters. The cylinder diameter is 61.7 millimeters. The piston stroke is 58 millimeters. The maximum power in kilowatts is 9.9, and in horsepower it is 13.5. The cylinder, piston, crankshaft and main bearings are lubricated with gasoline and oil. Engine oil is poured into the box and clutch and checked with a dipstick.
Photo report: Disassembling the engine of the Voskhod-3M motorcycle
The engine that we will be disassembling today had some problem with gear shifting. The owner seemed to start disassembling it, removed the generator, clutch basket, cylinder, and then something went wrong with him. In general, he took it, threw it into a bag and brought it to me with all the “gibles” for repairs.
Remove the kickstarter shaft.
Using round-nose pliers, remove the retaining ring from the piston pin boss, push it out and remove the piston from the connecting rod.
We take out the separator from the upper head of the connecting rod and hide it somewhere further.
We unscrew all the bolts holding the crankcase halves together and knock out the guide bushings (if any). Typically, guide bushings are pressed into holes through which the engine is attached to the frame.
We take a mallet and strike the crankcase halves evenly from all sides (“pricking the engine”).
Before disassembling the engine, do not forget to put the drive sprocket on the output (secondary) shaft of the gearbox. If this is not done, then during disassembly, the secondary shaft jumps out of the cage and all the bearing rollers scatter in different directions. The videos are then very difficult to find. It is better to remove the secondary shaft over some kind of pallet or container, so that if something happens, the rollers will not disappear from you.
Ignition and carburetor
It is these two components that, as a rule, determine the stability of the engine. Often, interruptions in the crankshaft rotation speed, loss of traction, and difficulties starting the engine are associated precisely with their malfunctions. Repairing the ignition and carburetor usually comes down to adjusting them. Setting the ignition includes setting the gap between the coil core and the sensor magnet within 0.295...0.305 mm. The piston ignition timing should be 3.5-5 mm to top dead center. Adjusting the carburetor is somewhat more difficult. If you are repairing a Voskhod-3M motorcycle, then you will have to deal with the K65V carburetor, and the main tools will be the quality and quantity screws included in its design. Using the first, you can lean or enrich the mixture - change the proportion of fuel and air entering the cylinder. The second determines its volume per working cycle. With the standard setting, the quality screw is screwed in completely and then unscrewed half a turn. Then the rotation of the quantity screw achieves the minimum stable speed and the quality of the mixture is re-adjusted. Finding the optimal adjustment balance is a search for maximum traction and stability with minimum fuel consumption.
Photo report: How to disassemble the Voskhod engine?
It is not clear why Voskhods have gained fame as unreliable and capricious motorcycles. You might think that Jupiter or Ant is much better than Sunrise. However, this opinion still exists in the motorcycle community. Well, okay, if there is such an opinion, then so be it.
Someone had already “overhauled” the engine before us, then we drove it a little, removed the cylinder for boring and rolled it into the garage for the winter. While the motorcycle was standing in the barn, water began to flow into the engine... And when spring came to the yard, the owner wanted some drive... Well, let's give him some drive.
Removing the generator
We slightly unscrew the generator rotor mounting bolt, attach the rotor with a puller, rest the puller bolt against the rotor mounting bolt and pull the rotor off the crankshaft axle
We pick out the key and put it somewhere away. Help: painted oil seals are a sure sign of collective farm repairs (experience)! If you decide to buy a Voskhod and see that the seals are painted, check the engine a hundred times and only then agree to purchase.
Tools
- Large flathead screwdriver
- Puller for removing the drive sprocket of a motor transmission
- Puller for removing the generator rotor
- Puller for loosening the clutch basket nut
- Head for 11, 14, 19
- Hook for removing clutch springs
- Small hammer
- Wish
Removing the piston
We unscrew the four nuts on the head, remove the head from the studs, remove the cylinder, remove the retaining ring from the piston boss, push out the piston pin, remove the piston and remove the separator
Preparation
Russian is Russian, so until we process all the parts properly with a file before installation, nothing will work out...
Insert the cylinder rings and use a feeler gauge to measure the gap in the lock.
- If the gap is less than normal, file the ends of the rings with a file
To reduce engine noise and speed up the ring grinding process, remove small chamfers on their working edges (preferably)
To improve lubrication of the piston pin, use a 5-6 mm drill to drill through holes in the piston bosses (optional)
We remove flashes and deposits of metal in the cylinder windows and round the edges along which the rings go
After finishing work, we thoroughly wash all the parts, prepare a clean work area and begin assembly.
Removing the kickstarter
We put the claw on the kickstarter shaft, pull the shaft towards us, unwind the return spring and remove the kickstarter from the shaft
Second jamb
Cracks often appear where the kickstarter shaft enters the crankcase. It is advisable to weld crankcase cracks
Engine disassembly
We unscrew the bolts holding the crankcase together. There should be 14 bolts
We heat the crankcase connector with a hairdryer, apply gentle blows to the protruding shafts through a wooden spacer until the engine is halved
The third jamb
The crankcase gasket was installed crookedly, so much so that it did not even cover the crank chamber connector
Jamb four
The main bearing was closed. He died quickly
Fifth jamb
The gearbox secondary shaft bearing was not assembled correctly: the rollers should be separated by a ring, but on this engine a ring was not installed between the rollers
So much for a major “repair”, the painted oil seals are proof of this. Now think: is it worth buying a motorcycle after a major overhaul or is it better to buy one that has been worn out, but has never been chipped.
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