Choosing an outboard motor is always about balancing budget, reliability and desired power. In the 90-horsepower segment, which allows heavy PVC and light boats to plane, Chinese-made models built under licenses from well-known brands are a special feature. Impulse 90It is often seen as an affordable alternative to the famous Japanese counterparts.
This model attracts the attention of water engines with its pricing policy and declared specifications. Many owners who switch from low-power 15-30 hp to a full-fledged 90-horsepower engine wonder about the real resource and economy of this device.
In this article, we will discuss in detail the technical nuances, features of the installation and operation of the engine, as well as touch on issues that are rarely covered in official manuals. Impulse 90 And it's not just a dry retelling of the specifications, it's an analysis of the real engineering behind the unit.
Technical specifications and design
Heart. Impulse 90 It's a two-cylinder two-stroke engine with a loop purge, and the engineers' choice is to get the most traction at the lowest weight, and the cylinder capacity is 1,696 cubic centimeters, which is standard for this power class, and the ignition system here is electronic (CDI), which ensures a stable start even after long downtime.
The most important element of the design is the cooling system. Impulse 90 Forced water cooling is applied with a centrifugal pump located in lower unit. Critically, the impeller pump is made of high-quality rubber, but sensitive to work "dry"The start of the motor is carried out by an electric starter, although manual start (the cable) is also provided as an emergency option, which increases the autonomy of swimming.
When considering the design, you can not ignore the control system. The engine is equipped with tiller control, although there are modifications for the remote tube (DR). The gear ratio of the gearbox is 2.08:1 (27:13), which provides excellent traction at low speeds and the ability to bring heavy boats to the plane. The weight of the engine in running order is about 36 kg, which makes it relatively easy for its class.
- 🚀 Power: 90 hp at 5000-5500 rpm.
- ⚖️ Weight: 36 kg (excluding oil and fuel).
- ⛽ Tank volume: 24 litres (removable).
- 🔧 Lubrication system: mixing gasoline with oil in a ratio of 1:50.
Fuel consumption and economy
The question of voraciousness of the engine is always on the edge, especially given the rise in prices for fuel. Impulse 90Like any two-stroke, it requires a fuel mixture, a break-in ratio of 1:25 and then 1:50. At cruising speeds (about 4,000-4,500 rpm), fuel consumption is about 25-30 liters per hour, an average that is comparable to competitors.
But the real picture depends on a lot of factors: propeller, boat load and bottom condition. If you use a standard 13x19 propeller, the flow rate can reach 35 liters at full gas, but at such speeds the engine does not work for a long time. For economical trolling or long distances, it is better to use a screw with a large pitch, which will keep the speed in the zone of maximum torque.
There's a common misconception that two-stroke engines always eat more than four-stroke engines. Yes, in liters it does, but if you count the mass of the way you've traveled, the difference is not so catastrophic, especially on the gliser. Impulse 90 He shows himself to be quite an economical "worker", if not to twist him constantly in the cutoff.
Use a transparent wall measuring tank and stopwatch to accurately measure the flow. Eye or gas station checks often give an error of up to 30%.
Installation and initial start-up
Mounting the motor on a transom is a careful procedure, and the height of the lower unit installation should be such that the anti-cavitation plate is 2-3 cm below the bottom of the boat when moving. A too deep landing will increase the water resistance, and too high will lead to the capture of air by the screw. The fastening is carried out by two bolts through the transmuter bar, the puff must be monitored regularly.
The first start after purchase is a stressful moment for the owner. Make sure that the fuel pear of the pump is rigid, and there are no air jams in the system. Before jerking the starter or pressing a button, you need to press the enrichment button of the mixture 3-5 times (if it is in a specific modification) or use the "suction". After starting, let the engine warm up at idle speeds for at least 3-5 minutes.
⚠️ Attention: Never launch. Impulse 90 Out of water or without water supply to the water intake for more than 10-15 seconds, this is guaranteed to overheat and deform the impeller pump and sealing osteoils.
Checking the thermostat (if the model is equipped with a thermostat) is performed visually by the stream of the "control", it should be smooth and powerful. If the jet is intermittent or absent, immediately shut down the engine and check the cooling system for clogging.
☑️ Check before the first launch
Engine break-in procedure
Running is the generation of the engine life. Impulse 90 It's 10 hours, and ignoring this phase will lead to lower compression and higher oil consumption in the future, and in the first hours of operation, the piston rings are laundered to the cylinders, so the operating modes should be gentle.
In the first 5 hours, it is recommended to operate the engine at speeds not exceeding 50% of the maximum power (about 2500-3000 rpm). Avoid long work in one mode, it is useful to periodically change the gas. The next 5 hours you can increase the load to 70-80%, making short accelerations to full gas, but not lingering in this mode for longer than 1-2 minutes.
After 10 hours, you need to replace the spark plug and conduct a visual inspection of the nodes. The color of the coar on the candle will tell you the correctness of the preparation of the mixture: brick shade is normal, black is overenrichment, white is overheating or poor mixture. It is also recommended to check the tightening of all bolt joints, since the vibration in the first hours could weaken them.
Can I run the engine in a barrel?
Theoretically, it's possible, but it's not recommended. In a barrel, the motor doesn't really get the screw load, and the laundry of the rings is not correct. It's better to run in water, going against the current or the wind to create a load.
Table of main parameters
For convenience of comparison The Impulse 90 with other models, we've put the key data into a single table, and these specifications will help you determine the compatibility of the engine and your boat.
| Parameter | Meaning | Unit of measurement |
|---|---|---|
| Workload | 1696 | cm3 |
| Maximum power | 66.2 | kW |
| Range of revolutions | 4500-5500 | min |
| Type of launch | Electrical starter | - |
| Recommended screw | 13x19 | lens |
Maintenance and typical faults
Regular maintenance is the key to a long life Impulse 90Every 50 hours of motorsport, you need to inspect and lubricate the nodes. Pay special attention to lower unit: there is oil in the redctor, which you need to change after the first 10 hours, and then every 100 hours or once a season. The color of the oil should be transparent; if it has become an emulsion (like coffee with milk), then the leakiness of the oils is broken.
One of the common problems is clogging of the carburetor, low-quality gasoline quickly disables the jellyplants, use high-quality two-stroke oils and a stable AI-92 for prevention, and also monitor the condition of the fuel filter-sludge located on the engine, it must be cleaned at each refueling.
Vibration is another aspect that can be a concern to owners: it is often caused by an imbalance in the screw or damage to its blades; regularly inspect the screw for chipped and wound fishing nets; even a small thread wound on a lower unit can lead to overheating of the obble and water entering the gearbox.
The main enemy of the two-stroke engine is poor-quality oil and the wrong proportion of the mixture. The savings in oil are 2-3 times cheaper than the engine, but lead to its overhaul.
⚠️ Attention: When storing the engine in the off-season, be sure to drain the fuel from the carburetor. The remaining gasoline evaporates, leaving resinous deposits that clog the jelly and make starting in the spring extremely difficult.
Frequently Asked Questions (FAQ)
Which screw is better to put on the Impulse 90 for PVC boats 3.8 meters?
For a boat 3.8 meters long with a full load (2-3 people + equipment), the optimal propeller with a pitch of 17-18 inches. Standard 19th step can "not reach" the speed, and the engine will work in tension, which is harmful to the piston. If the boat is light and people are few, you can leave the 19th step for maximum speed.
Which oil is best used for the mixture?
Use only oils labeled TC-W3. Well-established brands Motul, Ravenol, ZIC. Mineral oils are cheaper, but synthetics or semisynthetics give less soak and better lubrication, which prolongs the life of the engine. Proportion strictly according to the instructions: 1:50 for the break-in motor.
Why does the engine stop on idle?
Most often, the reason is clogging of the carburetor's idle jeeler or sucking air through the gasket between the carburetor and the cylinder, and it's also worth checking the adjustment of the gas cable and the state of the spark plug. If the candle is black, the mixture is too rich, you need to adjust the carburetor.
Can I use Impulse 90 for trolling?
Yes, but with caution, two-stroke engines at low speeds tend to foul candles with soot. Periodically (every 30-40 minutes) let the engine gass at medium speeds to clear the combustion chamber. Also keep an eye on the temperature, as the pump pumps water less efficiently when running low.
Where is the safety lock on the electric starter?
The fuse is usually located under the starter's protective cover or next to the ignition lock on the tiller. It is a plastic cap with a melting insert inside. If the starter is not spinning, but the battery is charged, first check its integrity.