How Does a Lower Unit Work?
- Driveshaft: How it Works & Maintenance The driveshaft is responsible for converting the rotation power from the motor to the gear case. ...
- Water Pump: How it Works & Maintenance The water pump delivers water through the engine to cool it. ...
- Shift Shaft: How it Works & Maintenance ...
- Gearbox: How it Works & Maintenance ...
- Oil Seals: How it Works & Maintenance ...
Full Answer
How does Yamaha lower unit work?
Yamaha Lower Unit helps in changing the power of engine belongs to Yamaha outboard to rotation of the propeller shaft that moves the propeller. Moving the propeller moves the boat. Lower unit an essential part of your outboard and ultimately helps your boat move.
How does an outboard lower unit work?
How an outboard lower unit works. As said in the previous page. The torque made by the power head is transmitted along the lower unit's drive shaft. To turn the prop the drive shaft must engage a set of gears and also the torque must be bent 90 degrees.
What is an outboard lower unit (gearcase)?
The lower unit (or gearcase) is the part of the outboard that takes the power and rotation from the engine and transfers them to the prop shaft and the propeller. How an Outboard Lower Unit Works | How an Outboard Gearbox Works | Boats.net
How to make a lower unit stand?
How To Make A Lower Unit Stand! Using four pieces of 2 X 10 or 2 X 12 wood. Place two 18-inch pieces about two inches apart. Then screw a 12-inch piece on both sides of the 18-inch pieces. There are a few different styles that can be made, but how you use it will determine what style is best for you.
What is the drive shaft in a gearbox?
What is the pinion gear in a drive shaft?
Why is my outboard noisy?
How does a gearbox seal work?
What happens when a shift shaft is put in forward position?
Why do you need to inspect the oil seal on a prop shaft?
How to prevent premature dog clutch wear?
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How does an outboard lower unit work?
0:179:32How an Outboard Lower Unit Works | Boats.net - YouTubeYouTubeStart of suggested clipEnd of suggested clipThe forward and reverse gears. That follow with the prop shaft. You look towards the top there's aMoreThe forward and reverse gears. That follow with the prop shaft. You look towards the top there's a new name it's spawned around the top this is what seats into the power hit.
How do you know when your lower unit goes out?
If you notice oil leaking from the propeller shaft, it's a sign that the seals in the lower unit are damaged. Oil leaks can also be caused by a cracked case or a bent propeller shaft. If you notice that the propeller is bent or damaged, it's a sign that the lower unit is probably damaged.
Why am I getting water in my lower unit?
This is usually caused by a leaky seal due to fishing line or other fine debris that got wrapped around your prop shaft. If you have water in your oil, don't finish the oil change because water will just seep back in when you get out on the water.
Can you run an outboard motor without the lower unit?
Yes. It's just an electric motor with its drive shaft detached.
Why is lower unit oil black?
The lower unit is made from aluminum. It could be that aluminum is going though oxidization and turning the gear oil black.
How often should you change lower unit oil?
every one-hundred hoursMuch like how cars should receive an oil change every thirty-thousand miles, your outboard lower unit oil requires changing every one-hundred hours the boat is in operating. Without regular lower unit oil changes, you run the risk of damage occurring in the engine.
What happens if water gets in lower unit of outboard motor?
You have to change that oil and find out were it is leaking, If the problem is not address the water will ruin the lower unit gears, (drain the oil/water mix and put fresh oil back in). The lower unit needs to come off the engine, the water pump seals and area need to be checked so have your pump changed/replaced.
What kind of oil do you put in a lower unit?
You can use any brand of lubricant that has a grade designation of API GL5 SAE 80 or 90 weight. Make sure you do not mix different oil brands or weights. into the BOTTOM drain hole. Then slowly squeeze the bottle to force the oil into the lower unit.
What do you do if your lower unit oil is cloudy?
That milky color and consistency is most likely due to water intrusion. It will not break down from use and get lighter, like other oils as it breaks down and gets used it darkens. Time to change seals and when you do your water pump do the whole kit and not just the impeller.
Should I leave my boat motor up or down?
The best way is to either leave the motor on the boat or on an engine stand in an upright position, not tilted. If neither of these are an option, try to make sure that the engine is in an upright, self-draining position. If you can't do this, be sure that the cooling system is drained completely.
Is it OK to start an outboard out of water?
Running the engine without a water source for any length of time will cause damage, so you'll need to attach a hose to the motor's water intakes. Some newer motors have built-in attachments that accept a hose nozzle.
Is it better to store your boat motor up or down?
Don't Store the Motor Tilted Up When you park the boat for the winter keep the motor trimmed or tilted down, especially if it's outdoors. This will allow all of the water to drain out of the motor's cooling system.
How long do outboard lower units last?
Boat motors typically last at least 2,000-3,000 hours before they need serious maintenance. Inboard motors will sometimes last longer because they are more protected from wear and tear.
How do I know if my lower unit oil is bad?
2:374:12Changing Your Lower Unit Oil - YouTubeYouTubeStart of suggested clipEnd of suggested clipThe oil in this outboard looks fine while the oil is draining clean up the drain. And vent plugMoreThe oil in this outboard looks fine while the oil is draining clean up the drain. And vent plug screws. And install new sealing o-rings.
How much does it cost to replace a lower unit on a boat?
A typical set of parts for the gearcase can cost $500-600 and may go higher if the gearcase is severely damaged. If you have your local mechanic repair the lower unit, his labor will run about $300-400 for this type of repair. The cost of the parts will be the same as above.
What does a spun prop feel like?
A spun hub feels like a loss of power with excessive RPM. You will likely feel the prop slipping at high RPM.
What is the drive shaft in a gearbox?
The drive shaft enters the gearbox and ends at a pinion gear . The pinion gear is permanently engaged with the forward gear and the reverse gear, so when the driveshaft is rotating, the pinion gear is rotating, and the forward and reverse gears are rotating. Shims behind the pinion, forward and reverse gears keep the gears properly engaged with one another, with no play between them.
What is the pinion gear in a drive shaft?
The drive shaft enters the gearbox and ends at a pinion gear. The pinion gear is permanently engaged with the forward gear and the reverse gear, so when the driveshaft is rotating, the pinion gear is rotating, and the forward and reverse gears are rotating.
Why is my outboard noisy?
The pinion, forward and reverse gear shims also wear over time. When this happens, the transfer of power between driveshaft and prop shaft is slightly reduced, and your outboard will feel like it's losing performance. The gearbox will also be noisier than usual, as the loose gears "chatter" together. If you think your outboard is down on power or is excessively noisy, it might be time to inspect and replace the gearbox shims.
How does a gearbox seal work?
How It Works: To keep the lubricating oil within the gearbox and to prevent water from entering the gearcase, there are a number of oil seals and O-rings in the lower unit. These seals are: 1 Driveshaft oil seal 2 Prop shaft oil seal 3 Shift shaft oil seal 4 Shift shaft plate O-ring 5 Gearbox bearing housing O-rings
What happens when a shift shaft is put in forward position?
When the shift shaft is put into its "forward" position, it engages the dog clutch with the forward gear, which causes the dog clutch (and the prop shaft) to rotate in one direction.
Why do you need to inspect the oil seal on a prop shaft?
Maintenance and Repair: Because the prop shaft oil seal is exposed and prone to damage, you should inspect it regularly and replace it if it is worn or leaking.
How to prevent premature dog clutch wear?
To prevent premature dog clutch wear, always shift in and out of gear at the lowest possible RPM. Also, make sure your rigging (throttle cables, shift cables, etc.) is well maintained so they aren't stretched, which gives your engine incorrect inputs. The pinion, forward and reverse gear shims also wear over time.
How does a propeller pull?
The one in the picture that looks like and flexible "L" on the left side. If the rod in the center of the propeller shaft is pulled forward it engages the forward gear, if pushed back it engages the reverse gear. If it ends up in the center it in in neutral "gear".
What is the dog clutch?
Which really is just a toothed gear that meshes into the center of either the forward or reverse gears.
Which way does the drive shaft turn?
The drive shaft is always turning clockwise as the engine is running. The drive gear is coupled to the forward and reverse gears, these gears spin in opposite directions, they too are also always turning as long as the engine is turning. The forward gear spins in a clockwise direction and the reverse gear in a counter clockwise direction.
How Good Are Your Carpentry Skills?
To make the quick and easy stand, you don’t need to have 50 years of fine cabinetry to make a stand to hold a lower unit while you change out the impeller.
Why do you leave a space in the middle of a 1x4?
Leaving a space in the middle of the 1 X 4’s so that the lower unit skeg can fit down into them and rest the bullet of the gear case on them.
Why is it important to have a case holder?
Having a DIY gear case holder is important because it will help to make the job easier. Having a job to do is not always enjoyable, especially when you are trying to get back out to the lake.
What is a professional lower unit stand?
Most commonly, a professional lower unit stand that you buy from a major manufacturer. Is going to have the gear case sitting in a yoke that lets the lower unit rest on the anti-ventilation plate.
How to make a sandbox out of wood?
Using four pieces of 2 X 10 or 2 X 12 wood. Place two 18-inch pieces about two inches apart. Then screw a 12-inch piece on both sides of the 18-inch pieces. There are a few different styles that can be made, but how you use it will determine what style is best for you. Here’s how you can decide!
Can you change out a water pump impeller without flipping it?
It will also hold the stand steady, so we can change out the water pump impeller without flipping the lower unit over!
Can you change the impeller on a boat engine?
Dropping the lower unit and changing out the impeller, on the other hand, can get tricky! Especially if you have nowhere to work on the lower unit.
How does a TENS unit work?
TENS units work by delivering small electrical impulses through electrodes that have adhesive pads to attach them to a person’s skin. These electrical impulses flood the nervous system, reducing its ability to transmit pain ...
What is a Tens unit?
A TENS unit has controls that allow people to administer an appropriate level of pain relief. People can achieve this by altering the following aspects of the electrical current: Intensity: A dial allows the user to adjust the intensity of the electrical stimulation.
What is the effect of electrical impulses on the nervous system?
These electrical impulses flood the nervous system, reducing its ability to transmit pain signals to the spinal cord and brain.
Why are tens units so convenient?
TENS units are also convenient because they are small, portable, and relatively discrete.
What is the frequency of a pulse?
Frequency: The frequency refers to the number of electrical pulses per second. High-frequency (HF) pulses range from 80 to 120 cycles per second and may help manage acute pain. Low-frequency (LF) pulses range from 1 to 20 cycles per second and are suitable for the treatment of chronic pain.
What is the purpose of needles in acupuncture?
Acupuncture is a practice that uses needles to stimulate the nerves beneath the skin at specific locations known as acupuncture points. Experts believe that this assists the body in producing endorphins.
What are the conditions that cause joint pain?
They may also alleviate pain that results from the following conditions: endometriosis. arthritis. sports injuries. multiple sclerosis. fibromyalgia. painful diabetic neuropathy.
Why Buy SEI Yamaha Lower Unit?
Replacement sterndrives this company include Alpha Gen I and Gen II. Parts can be interchanged with the Original Equipment Manufacturer (OEM). Outdrives manufactured by SEI are brand-new and that they don’t remanufacture. So you’re safe with such compatible and totally new out drives.
How long is a 20 inch drive shaft?
The actual length of the driveshafts across the OEM platforms are different. Examples are a 20 inch driveshaft for a Mercury outboard could actually measure 22 1/8”. This is considered a 20 inch driveshaft because it measures more than 20” but not enough for a 25” driveshaft.
What is a lower unit on a Yamaha outboard?
Yamaha Lower Unit helps in changing the power of engine belongs to Yamaha outboard to rotation of the propeller shaft that moves the propeller. Moving the propeller moves the boat. Lower unit an essential part of your outboard and ultimately helps your boat move. If you have yamaha outboard and lower unit is not working then make sure ...
What are the parts of an outboard Yamaha?
So keep it maintained for smooth journey. Outboard consists of three major parts; Powerhead (Engine), Midsection (Exhaust Housing) and Lower Unit (Gearbox or Gearcase). Below are major Yamaha lower units that fit most of the outboards.
What is an OEM motor?
OEM parts: OEM stands for Original Equipment Manufacturer so it's clear from name that these are the parts directly made by outboard motor's manufacturer and not by third party. So these parts fits to the specification of the model of outboard motor in your use.
How long is SEI warranty?
What about Warranty? This is another thing that makes SEI drives standout in the market with 3 year fault-free warranty.
What is the difference between a 76 degree and a 90 degree?
90 degree is for 2.6 liter engine and 76 degree is 3.1 & 3.3 liter engine. These numbers like 2.6, 3.1 and 3.3 refer to the size of the engine. Specially the volume of air that It displaces on the basis of the number of cylinders.
What is the drive shaft in a gearbox?
The drive shaft enters the gearbox and ends at a pinion gear . The pinion gear is permanently engaged with the forward gear and the reverse gear, so when the driveshaft is rotating, the pinion gear is rotating, and the forward and reverse gears are rotating. Shims behind the pinion, forward and reverse gears keep the gears properly engaged with one another, with no play between them.
What is the pinion gear in a drive shaft?
The drive shaft enters the gearbox and ends at a pinion gear. The pinion gear is permanently engaged with the forward gear and the reverse gear, so when the driveshaft is rotating, the pinion gear is rotating, and the forward and reverse gears are rotating.
Why is my outboard noisy?
The pinion, forward and reverse gear shims also wear over time. When this happens, the transfer of power between driveshaft and prop shaft is slightly reduced, and your outboard will feel like it's losing performance. The gearbox will also be noisier than usual, as the loose gears "chatter" together. If you think your outboard is down on power or is excessively noisy, it might be time to inspect and replace the gearbox shims.
How does a gearbox seal work?
How It Works: To keep the lubricating oil within the gearbox and to prevent water from entering the gearcase, there are a number of oil seals and O-rings in the lower unit. These seals are: 1 Driveshaft oil seal 2 Prop shaft oil seal 3 Shift shaft oil seal 4 Shift shaft plate O-ring 5 Gearbox bearing housing O-rings
What happens when a shift shaft is put in forward position?
When the shift shaft is put into its "forward" position, it engages the dog clutch with the forward gear, which causes the dog clutch (and the prop shaft) to rotate in one direction.
Why do you need to inspect the oil seal on a prop shaft?
Maintenance and Repair: Because the prop shaft oil seal is exposed and prone to damage, you should inspect it regularly and replace it if it is worn or leaking.
How to prevent premature dog clutch wear?
To prevent premature dog clutch wear, always shift in and out of gear at the lowest possible RPM. Also, make sure your rigging (throttle cables, shift cables, etc.) is well maintained so they aren't stretched, which gives your engine incorrect inputs. The pinion, forward and reverse gear shims also wear over time.
