The 9.9 hp outboard motor is one of the most popular solutions for small boat owners, and often the basic configurations of such engines involve only manual start-up, which can be a significant problem, especially in the cold season or when frequent trips to the water. electric starter Turns the operation of equipment from physical activity into a comfortable process that requires only a light turn of the key or pressing a button.
Owners Tohatsu, Yamaha or Hidea It's often questioned whether this is a good idea, given that 9.9 forces are not a 200-horsepower beast that can't be pulled by hand, but the failure rate of manual scrolling starters increases in proportion to hours of work, and comfort on fishing or cruising becomes a priority. Modern lithium batteries allow you to implement the scheme of electric start even on compact motors without critical weight gain.
In this article, we will discuss in detail the technical details necessary for the successful implementation of the project: you will learn which models of motors have hidden readiness for installation, how to choose the right battery and avoid common errors in wiring installation.
Technical compatibility and engine preparation
The first step to success is to define exactly the model of your engine. Not all 9.9 hp engines are structurally ready to accept an electric starter without major alterations. Yamaha or TohatsuThey release unified cylinder blocks, where the openings under the starter anchor are already provided, but the knot and flywheel may differ, and you need to find the model marking, which is usually located on the motor bracket or on the cylinder block.
The key element of the system is the flywheel. The electric starter requires a flywheel with a pressed cogwheel. If you have a manual flywheel on your motor, you'll have to replace it. It's a time-consuming operation that requires removing the flywheel cover, unscrewing the crankshaft nut (often with a special detacher) and carefully installing the new component. The gap between the Bendix gear and the flywheel crown It should be strictly regulated, otherwise teeth breakage is possible.
You also need to check for a seat on the crankcase. In some cases, even if there are holes, they may be closed with technological plugs or the thread in them may not be fully drilled. Carefully examine the lower part of the motor in the base area.
Be sure to check the status of the ignition system. When installing an electric starter, the load on the battery increases many times over, and a weak spark can cause the engine to turn but not start. The spark plugs should be in perfect condition, with the right gap.
Selection of starter and necessary components
The market offers a variety of components, from original parts to budget counterparts. The original, of course, guarantees the resource and accuracy of fitting, but its cost can be comparable to the price of the used engine. Hidea or ParsunThey can be a great solution if you have a good installation, and the key is to pay attention to the number of strands of the Bendix gear and the direction of rotation.
Besides the electric motor itself, you will need a starter relay (traction relay) that commutes large currents. The standard relay often comes complete with the starter, but for reliability it is better to use marine versions with protection from moisture and salty environment. wiring also plays a critical role: the wire cross section must be sufficient to pass the starting current without significant voltage losses.
List of necessary components for system assembly:
- ⚡ Electric starter assembled with bendix (necessarily with the correct number of teeth).
- 🔋 Traction relay with a protective casing and fasteners.
- 🔌 Start button or ignition key with appropriate marking.
- 🧶 Copper wire with a cross section of at least 16 mm2 for the power circuit.
- 🛡️ 20 to 30 ampere safety lock to protect the control circuit.
When choosing a starter, make sure that its body does not conflict with the engine housing. Sometimes a standard plastic casing has to be slightly trimmed or modified to allow the starter to enter the allotted space, which is especially true for motors with a compact layout.
Original or analog?
Original starters serve on average 2-3 times longer than cheap counterparts, but their price can reach 10-15 thousand rubles. Chinese starters for 2-3 thousand rubles often require preventive lubrication and replacement of bushings immediately after purchase. If you rarely go - enough analogue, for commercial use it is better to look for the original or high-quality OEM.
Selection of the battery
Installing a 9.9 hp electric starter changes the power supply requirements. If you used to have a small 7 Ah gel battery to run the sonar and the navigator, you now need a full starter battery. Start current can reach 80-120 Amps at the time of scrolling, and a weak battery will simply "sit down" after a few attempts.
The best choice will be a lead-acid battery type AGM These batteries hold the initiation current well, are not afraid of deep discharge as much as the starter batteries, and are safe to install inside the boat. Lithium-iron-phosphate (LiFePO4) batteries are also great, they are lighter and more compact, but require built-in BMS with protection from overload and low voltage, and also cost much more.
It is important to consider the weight of the battery. Installing a heavy battery in the stern can change the differentiation of a PVC boat or a small boat. Therefore, the placement of the battery should be planned in advance, perhaps by moving it closer to the centralized part of the vessel or using a special kunduk.
Table of comparison of types of batteries for the engine 9.9 hp:
| Type of AKB | Weight (roughly) | Start current | Cycle resource | Price. |
|---|---|---|---|---|
| Lead-acid (WET) | 12-15 kg | Highly | Low. | Low. |
| AGM / GEL | 10-13 kg | Very tall. | Medium. | Medium |
| LiFePO4 | 4-6 kg | Highly | Very tall. | High. |
Don't skimp on terminals and contacts. The oxidation of the contacts in salt water is instantaneous, which will cause the voltage to drop on the starter. Use only tinted copper terminals and be sure to treat the connections with a special lubricant to protect against corrosion.
When installing the battery in a PVC boat, be sure to use a hard box or mount. Motor vibration and waves can displace an unattached battery, resulting in short circuit or damage to the boat hull.
Connection scheme and wiring installation
Installation of the electrical circuit requires care and polarity. An error in connection can cause the generator diode bridge or the starter itself to burn. The standard connection scheme includes the battery, fuse, start button/key, starter relay and the electric motor itself. The relay is fed directly from the battery through the fuse, and the relay control goes through the start button.
Use a corrugated tube or shrinkage to lay the wires. The wires should not hang around or touch hot parts of the engine, such as a muffler or cylinder head. Secure the harnesses with plastic clamps to the motor frame, avoiding high-vibration areas. Mass (minus) It should be connected directly to the cylinder block or to the battery terminal if it is located nearby, but it is better to duplicate the mass on the engine.
The sequence of actions in the assembly of the chain:
- 🔧 Disconnect the battery's negative terminal before work begins.
- 🔌 Install the starter relay in a splash-proof place, preferably on the motor bracket.
- ⚡ Lay a thick wire from the battery plus to the power contact of the relay.
- 🔋 Connect the second power contact of the relay to the starter's plus terminal.
- 🎛️ Conduct a thin control wire from the start button to the control contact of the relay.
If you already have the wiring for the electric starter on your motor, it's a little bit easier. You just have to find the appropriate contacts in the connection chip and connect them to the button. The colors of the wires may vary from manufacturer to manufacturer, so you have a multimeter and a circuit for your model. Tohatsu M9.9 or Yamaha 9.9 I'll be sure.
☑️ Check before the first launch
Installation process: step-by-step instructions
The installation begins with the removal of the safety casing and the flywheel cover. Be careful not to lose the washers or damage the gaskets. Remove the old flywheel using a special detachment. Don't try to knock it down with a hammer - this can damage the kneeshaft. After removing the flywheel, clear the landing place of dirt and old lubrication.
Install a new flywheel with a cogwheel. Make sure it sits to the stop. Next, install the starter itself. When you install it, check the ease of rotation of the bendix gear. It should go out and back freely. If the gear gets stuck, you may need to adjust the thickness of the pads under the starter.
⚠️ Attention: Before final assembly, check the starter without load (no flywheel installation) by simply applying power. Make sure the bendix is ejected in the right direction and does not affect the crankcase body. After that, install the flywheel and check for tooth engagement.
Twisting the flywheel nut with the recommended tightening moment. Set the flywheel cover and the protective cover. If the starter prevents the casing from closing, carefully cut the required opening in the plastic, treating the edges with a file so that there are no sharp edges. Connect the battery and test start.
After the first start, listen carefully to the sound of the engine. An extraneous metal clang may indicate improper engagement of the gears, in which case the engine must be silenced and the assembly must be re-defected.
The quality of the starter installation depends 90% on the accuracy of the flywheel positioning and the condition of the cogwreath. Any distortion will lead to rapid wear or jamming.
Maintenance and typical faults
The electric starter, like any mechanical assembly, requires periodic maintenance, the main problem is getting moisture and salt inside the mechanism. It is recommended to remove the starter once a season, clean it of dirt and lubricate the shaft and gear of the bendix with refractory lubricant. Litol It can be washed out, so it is better to use specialized marine lubricants.
A common problem is oxidation of the contacts. Even with protection, over time, the terminals will become coated, increasing resistance. This causes the starter to spin sluggishly or click, but does not turn the engine. Regular cleaning of the terminals and checking the voltage at the starter entrance will help to avoid surprises on the water.
Typical symptoms of malfunctions:
- 🔋 The starter clicks, but does not twist - the battery is discharged or the terminals are oxidized.
- ⚙️ You can hear the squeal, but there is no engagement - wear of the bendix teeth or flywheel crown.
- 💨 The starter is spinning, but the engine does not start - the problem is in the ignition system or fuel, not in the starter.
- 🔥 Smell of smoke or smoke is a short circuit in the windings of the starter or overheating of the wiring.
If the motor has not been used for a long time, be sure to check the battery level before starting. Deep discharge is fatal for lead batteries. In winter, the battery is better stored in a warm room, fully charged.
What to do if the starter is stuck on the water?
If the starter is stuck in the extended position and the engine does not start, do not try to twist it by force. Remove the casing and carefully, using a screwdriver or mounting blade, try to squeeze the bendix back into the starter body, often allowing you to temporarily start the engine or at least to drive the boat away.
Frequently Asked Questions (FAQ)
Can I install an electric starter on a two-stroke engine 9.9 hp?
The principle of installation on two-stroke motors (for example, the Tohatsu M9.9B old Yamaha) It is similar to the four-stroke, the main thing is to find a compatible flywheel and starter that fits the seats. On two-strokes, it is often even easier to find a place to place components due to the simpler design of the cylinder block.
Will the weight of the engine increase after installation?
The starter itself adds about 1-1.5 kg to the weight of the engine. The main weight adds the battery (from 4 to 15 kg depending on the type). However, this weight is distributed: the engine becomes slightly heavier, but the battery usually sits in the boat's hunk, which can even improve the balance of the vessel, weighting the stern or center.
Do I need to change the generator when installing an electric starter?
In most cases, 9.9 hp engines have a standard lighting coil (if any) or magdino sufficient to recharge the battery while driving, unless powerful additional equipment is used. However, for full charging of the battery, it is recommended to use an external stationary charging device after each sortie.
How much does it cost to rework the 9.9 engine for an electric starter?
The budget can range from 5,000 to 20,000 rubles or more, depending on whether you buy original parts, used disassembly kits or new Chinese counterparts, and the service wizard's work will also make up a significant portion of the amount, unless you plan to do everything yourself.