Tuning Izh Jupiter-5: Engine, suspension, appearance

The IZH Jupiter-5 motorcycle was produced by the Izhevsk Machine-Building Plant from 1985 to 2008. In the USSR, it was a direct competitor to models from the famous Czech motorcycle manufacturer Java. Many of the cars produced are still on the roads of our country today. They are reliable and unpretentious, however, their technical characteristics and appearance no longer meet modern requirements. Tuning IZ Jupiter-5 helps correct the situation.

You need to redo it wisely

You can find a lot of materials on this topic on the Internet. But they should be treated with great caution. Some recommendations openly contradict common sense; the result of other alterations may be unpredictable. Let's try to help with advice to those who decided to do the tuning of Jupiter 5 with their own hands.

There are several directions for making changes to the design of the popular model:

Correction of the appearance of the motorcycle.
Modification or alteration of the suspension.
Engine tuning.

Let's consider each of them separately.

Installing a tachometer on Izh Jupiter 5

Very often, owners of this model change the standard tachometer and the dashboard in general. An excellent and inexpensive analogue would be the dashboard from a VAZ 2106 car. You can take a speedometer, tachometer and temperature sensor from the car. All these parts fit perfectly into standard motorcycle holes. Optionally, LED lighting can be installed on the new dashboard.

Correction of motorcycle appearance

Changing your appearance can happen in different ways. Among the most common:

Fairing installation.
Replacing the fuel tank.
Seat modification.
Motorcycle painting.

Fairing installation. This is the first thing that many lovers of modifying the appearance of motorcycles undertake. Although it is possible to cope with such a task, it should be recognized that the development of such components is a complex task that requires specific skills. The enterprises employ entire groups of specialists engaged in the design of fairings.

Previously, plaza development methods were used for this, but today automatic design systems are used. Finished parts are blown in wind tunnels so that their behavior in air flow can be assessed.

A person who does not have specific skills, despite all his talents, will most likely receive a result of dubious quality. The surface of the fairing will be uneven, which is clearly visible in the 5 photos posted online illustrating Jupiter tuning. The aerodynamics of the motorcycle may not improve, but worsen. Take all this into account before you decide to start making and installing a fairing.

Replacing the fuel tank is a completely justified decision. But you shouldn’t try to make a complex part yourself. This is not an easy task even for enterprises with special technological equipment. It’s smarter and easier to choose a ready-made fuel tank from some other motorcycle model.

Seat modification. You can try to make a change to the standard structure by upholstering it with a new material like leather or a good substitute, and installing a new filler. But the original seat has a significant mass. To reduce the weight of the motorcycle, it makes sense, as in the case of the fuel tank, to select a part from other equipment.

Painting IZ Jupiter-5 is a good thing. Here you can let your imagination run wild. But the best results can be achieved if you know the laws of color combinations or consult with a professional designer. Otherwise, instead of a stylish combination of contrasting colors, you can end up with an eye-catching color scheme.

If you are interested in long-lasting paintwork, first apply a layer of high-quality primer and refuse to use nitro paint, preferring alkyd or polyurethane enamels.

Improved technical characteristics

Engine

The Planet-5 engine is convenient for processing. Of course, owners always want to increase power. To do this, it is worth repressing the crankshaft, replacing the original bearings with bearings from the Java secondary shaft.

When disassembling, it is worth silvering the upper ring and the lower separator. After tuning the engine, its service life is reduced. So if you use the motorcycle for normal speed riding, you should not change anything in the engine, as this will greatly reduce the life of the tires

and rear clutch.

Cylinder

To increase the volume of the cylinder, cut off its upper part and bore the liner to 76 mm. After pumping the engine, the Planet can accelerate to 160 km/h.

Clutch

The factory clutch of the IZH Planet-5 copes well with normal loads. If you drive a lot and drive aggressively, you should think about replacing the clutch. Under increased load, the disks quickly fail, so it is worth replacing one of them with a thicker metal one. This will lead to a stronger compression of the springs, in which there will be no slipping and the clutch will be more difficult to squeeze.

Supercharging

Advanced mechanics can change the boost system. When tuning the IZH Planet motorcycle, do not forget to replace the air filter with a foreign one. High-quality air purification will increase the power of your “iron horse” and prevent the engine from overheating.

Piston

Lubricating the piston will increase friction between the side wall and the cylinder bore.

Thus, after spending some time and money on tuning the IZH Planet-5 motorcycle, you will get an excellent “iron friend”. "Planet" initially has good technical characteristics - excellent traction, high power, resistance to any type of road.

Add to this an affordable price, ease of maintenance and availability of the necessary parts, plus your skills and imagination - and you will get a motorcycle that will serve you faithfully in Russian off-road conditions for many years.

In addition to its decent appearance, Izh Planet 5 has excellent technical characteristics. The motorcycle is equipped with a single-cylinder two-stroke engine with a power of 22 hp. With. The fuel consumption and processing system requires a modest 5 liters. gasoline with stable driving at a speed of 90 km/h. In addition, this model of domestic motorcycle was one of the first to receive an air cooling system, which increases traction at low speeds.

The maximum speed of the motorcycle is 120 km/h. The unit performs well when driving off-road and does not require large expenses for maintenance. All this is the reason for the wild popularity of Izh Planet 5 from 1987 to the present day. After all, not every one of us can buy an expensive Harley Davidson. But many people are capable of paying 5–6 thousand rubles for a domestic motorcycle. In addition, the Izhevsk Machine Plant model is much easier to tune with your own hands, which cannot be said about the expensive American and Japanese “monsters”.

Refinement and modification of suspension

The original suspension of the IZH Jupiter-5 motorcycle is reliable and has good maintainability. It is not difficult to restore it, but better results can be obtained by making some changes to the design.

Installation of adjustable gas shock absorbers. Today on sale it is not difficult to find gas shock absorbers with suitable parameters that can be used in the design of the rear suspension for tuning IZ Jupiter-5. Ideally, you can improve ride comfort and improve the stability of the car on the highway.

Replacing the front fork. This is also possible, but most likely will require reworking its fastening.

Installing another handlebar is not prohibited if it does not worsen the ergonomics of the rider's seat.

How I decided to remove paint

It was necessary to have some kind of more or less durable grinder with an attachment made of Scotch Brite of suitable grain size, with Velcro on a cup with a rubber base. The surface would immediately be obtained without unnecessary scratches (although traces of metal molding and roughly cleaned welds previously hidden under paint would be visible).

Here, for example, are traces of metal molding:

Plus, the welds would have to be cleaned with a brush made of thin steel wires - also an angle grinder or a light high-speed reversible drill with such an attachment.

But instead of a so-so drill (and this is my drill in the photo and screws screws) with the money I had, I bought a semi-professional Skil grinder with a flexible shaft for 1390 rubles (790 rubles in the configuration without a flexible shaft; the flexible shaft resembles a speedometer cable in braid), I didn’t really use a single attachment from it. I asked him to sharpen an M6 bolt for a 3.2 mm collet, sawed it at the end and put small strips of sandpaper there.

This device made it possible to remove paint from the wheel rim without disassembling the wheel (without separating the rim and the wheel hub).

By the way, never clamp Chinese 3.0 mm bits with such a collet - they will turn and you will have to buy a whole set of collets (they are for different drills) in a radio parts store, which costs 200 rubles. Probably, the collet is 3.00 mm and not 3.20 mm and you need to clamp such attachments.

Included with the grinder was a pencil-shaped attachment made of diamond-coated steel. She was able to trim welds and draw on glass jars (the part with the largest diameter). These are sold in separate sets, but it’s still a shame to trim the metal with them.

You have to add machine oil to the flexible shaft of the grinder - in the place where it connects to the grinder, it then leaks out and ends up everywhere - on the floor, mask, face and clothes. It is better not to set the speed above positions 3, 4 or 5 during different operations set by the speed controller (there are 6 positions in total), since the motor in it starts to heat up too quickly at high speeds, the smell of insulation appears and you feel sorry for the sander.

Almost all the paint and rust was removed from the motorcycle with this sander. A grinder in addition to a grinder like this would be much faster, perhaps two or three days for all the parts including the frame. Some parts were cleaned by hand. It’s more pleasant to work by hand; there’s no rush like with a power tool. I would have done exactly this without a sander.

The best thing is a durable air compressor with sufficient liters per minute and air pressure capacity, and a few tools to go with it (a durable straight sander with easily replaceable bearings and a small angle sander with a rubber backing for Velcro). The rotation of the attachments in such tools simply stops and they do not get knocked out of your hands like a power tool - which often has a kilowatt of power to withstand possible overheating from prolonged use.

Engine tuning

The two-cylinder two-stroke engine with a working volume of 347.6 cubic meters was installed on the motorcycle. see most often has air cooling. The number of models released in recent years of production that used liquid cooling is negligible. The power that the engine develops is 24 hp. With. – can be increased by making some simple modifications:

Increase the compression ratio by removing about 1.5 mm from the adjacent plane of the block head. But this will require switching to fuel with an octane rating of AI-95 and making changes to the design of the crank mechanism. First of all, replacing the crankshaft bearings. You will also have to select spark plugs with a different heat rating.
Replacing crankshaft bearings. There is an opinion that only high-quality imported bearings can cope with increased loads. In fact, domestic developers have installed bearings with a large margin of safety. If you manage to purchase high-quality Russian analogues, they will do the job perfectly. Trying to change the size of the crankshaft journals is simply harmful. The thickness of their hardening layer is small and when more than 1 mm is removed from the surface of the journal, the service life of the part will sharply decrease.
Replacement or modification of pistons. The stock parts aren't that bad. Don't rush to look for a replacement for them. To increase power, it will be enough to lighten the pistons by removing casting flash and excess material from them. Parts should be carefully adjusted according to weight. It is desirable that the difference does not exceed hundredths of a gram. Such simple engine tuning will be more effective than installing a zero-resistance air filter or a direct-flow muffler. Although it is, of course, possible to install forward flow on IZ Jupiter-5.
Installing another carburetor. If possible, it's worth shelling out for a good Mikuni carburetor. Don't go for a large diffuser size. The standard diameter of 32 mm will be quite sufficient. But it’s definitely worth removing the protrusions on the intake and exhaust manifolds and polishing the internal channels of these parts. This will not only provide an increase in power, but will also help reduce fuel consumption below five liters.
Replacement of the ignition system. Installing BSZ on IZ Jupiter-5 only makes sense if you intend to use imported components. Most likely, the quality of domestic components will reduce all the advantages of the contactless ignition system to zero and the rework will not give the desired result.

Do not forget that increased power will improve the acceleration dynamics of the motorcycle, but will not provide a significant increase in speed. To increase speed, you will have to change the transmission gear ratios, selecting different sprockets for the gearbox and rear wheel.

Silencing attachment

You can make such an attachment from the old muffler of the “fifth” or “fourth” “Jupiter” or the “fourth” - “third” “Planet”.
A cylindrical piece without partitions should be used to make the nozzle. The “flute” must be made of a heat-resistant material; the muffler connecting pipe from the Ural motorcycle may be suitable for this. Holes will need to be drilled in it, and the free space between the body and the tube should be filled with glass wool. The exhaust pipe can be left original. It should only be shortened a little and the connection should be welded rather than bolted.

The next step will be to improve the intake system. The minimum program would be to install a carburetor from the Planet-5 motorcycle, where the diffuser diameter is 32mm. To do this, it is necessary to cut the inlet windows in the pipe flange and cylinders a little. To significantly increase acceleration dynamics with simultaneous synchronous operation of the cylinders, two carburetors will be needed.

On foreign-made motorcycles, a carburetor for each cylinder has been installed for a long time and has become the norm. From the standard pipe you will need flanges with which to attach to the cylinders. In addition, it will be necessary to machine two aluminum bushings, and the carburetor mounting flange will need to be cut off from the Planeta inlet pipe.

The second flange can be taken from the old “Jupiter” carburetor. Welding of parts must be done with argon, after which the assembly must be adjusted until the gaps completely match. If small gaps have formed, they can be filled with epoxy or “cold welding”. When using epoxy glue, you can use aluminum filings or powder as a filler.

To ensure uniform traction up to acceleration of 100 km/h, use the K 65V from the Voskhod motorcycle. It is advisable to replace the main fuel jets, needles and nozzles; repair kits for these carburetors are relatively inexpensive on the market. The fuel level in the float chamber can be left the same. Having completed the carburetor, you can begin upgrading the air filter.

The original air filter installed on a motorcycle is not only unable to provide high-quality air purification, but also reduces engine power. In this case, you can buy an imported filter or use the upper part of the foam filter for the Voskhod motorcycle, which can cope with both installed carburetors, besides, it takes up little space and is very easy to maintain. Impregnation of foam rubber should be done with special oil for air filters. Getting such oil will not be difficult.

One of the most important jobs remains - finishing the cylinders and piston group. The engine from Jupiter-5 is more mature, so there will be much less fuss with it. In the figure, the red lines refer to the development of the modified “Sport” cylinders, the black lines show the standard “Classic” version. An increase in engine power can be achieved by trimming the upper edge of the exhaust window by 1.5-2mm.

To increase the power of the Yu-5 engine by increasing the speed, trim the upper edge of the exhaust window by 1.5-2 mm. A prerequisite is the same weight of the pistons, and the windows must coincide with the purge windows in the cylinders and in no case overlap them. The edges of the piston rings will need to be chamfered.

It will be necessary to lighten the piston pins by cutting them into a cone at the end. It is also necessary to chamfer the end of the fingers. The “tails” of the locking pins will need to be bitten off so that they are not cut off by the piston pin.

For further refinement, you will need to find a crankshaft that has a needle bearing in the upper part. Such a shaft can be found on the “liquid” Jupiter. This shaft is interchangeable with other models. To ensure better lubrication of the bearing, it will be necessary to drill two holes in the head, the diameter of which should be in the range of 3-3.5 mm, as is done on the Planet. As practice shows, standard aluminum separators installed at the factory are not reliable.

The cylinder heads will need to be tightened by cutting their ends on a lathe. The volume of the combustion chamber can be determined by the spill method; it should be within 19 cm3. It is not recommended to increase the compression ratio further, since the cylinder heads may lose rigidity. After all the modifications made, you will have to drive the AI-92. At the end, you will need to adjust the ignition angle and install new Brisk OT “Jawa” or PAL spark plugs.

Not tuning, but restoration

However, modernization is not the only way for owners of the popular model. After all, the age of many motorcycles has already exceeded two decades, which means that they can already be classified as rare. Restoring IZ Jupiter-5, restoring it and bringing it to its original state is also quite justified.

A legendary motorcycle that looks like it just rolled off the assembly line yesterday will attract no less attention than the tuned version. It’s just that how to properly restore equipment by performing qualified repairs often turns out to be much more difficult than remodeling it to your taste.

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In what cases is ignition adjustment necessary?

During the operation of the vehicle, the owner faces many problems. The most serious failure is related to the engine. In order to spend significant funds on major repairs, it is necessary to monitor the technical condition of the motorcycle and carry out preventive work, including adjusting the valves and valves (video author - Hana Rulyu).

If you do not monitor the SZ, then the motorcycle engine may not reveal its full potential and will not work at full capacity. This can lead to a reduction in its service life. An ignition adjustment is necessary if the engine is running poorly, the muffler or carburetor is firing. True, before setting up the SZ, you should make sure that the cause of the malfunction is in it.

It happens that the flywheel bolt, which connects the two halves of the crankshaft, comes loose, begins to play and does not work well. Sometimes he even cuts the key.

Setting up the SZ may be necessary after repairing the ignition switch Izh Jupiter 5. The installation and connection itself are carried out according to the diagram.

SZ diagram of the IZh motorcycle

Further modernization of the motor

Ideas for tuning the IZH Jupiter-5 engine involve sanding all residual irregularities on the unit. The intake and exhaust channels in the cylinders are finished in a similar way, bringing them to a smooth state. The bottom and surface of the pistons are polished in a similar way.

The standard crankshaft is too heavy. It is pressed out, the cheeks are ground to an outer diameter of 125 mm. Then the connecting rods are polished to a mirror finish. The improved crankshaft must be assembled and balanced. This type of modernization will increase the speed of the bike to 160 km/h.

The boosting of the IZH Jupiter-5 engine continues by increasing the compression. To do this, the combustion chambers are reduced by 1.5-2 mm by trimming. The operation is performed on a lathe, the heads are fixed in the chuck using mandrels. At this stage, it is important to ensure identical surface treatment (the volume of both working chambers must be exactly the same). An increase in the compression ratio entails a transition to AI-95 fuel with an early ignition setting (by several degrees). It is best to install an electronic analogue with automatic advance. This will make it possible to achieve high speed and spark formation at the right moment.

What do the owners say?

As reviews show, tuning the IZH Jupiter-5 with your own hands is quite possible. It is not limited to the manipulations indicated above. Since changing one unit leads to the need to transform the associated blocks, users recommend strengthening the chassis, balancing the wheel rims, and strengthening the pendulum. It is recommended to equip the standard frame with stiffeners. In addition, when modernizing, they often install disc brakes, a thicker front fork, and also paint the motorcycle in original color combinations. If you approach the tuning process correctly and competently, the result can exceed your wildest expectations.

Source

Silencing attachment

Holes will need to be drilled in it, and the free space between the body and the tube should be filled with glass wool. The exhaust pipe can be left original. It should only be shortened a little and the connection should be welded rather than bolted.