Let’s take a look at the most common sources of vibration:
- Damaged, loose, or obstructed propeller
- Loose engine mount
- Bad fuel pump
- Clogged or faulty fuel filter
- Misaligned harmonic balancer
Why does my boat vibrate when underwater?
At some point, all boats vibrate when underway. Often, onboard vibration is traced to the running gear and the engine. And since all the parts are interconnected, when something is worn out or not in alignment, it exerts extra stress on other components. Over time, as the boat owner, you can tell what each vibration means and what to do about it.
What should I do if my boat propeller is vibrating?
First thing we would do is inspect the propeller for dings that would throw it out of balance. The prop should be balanced to prevent vibration but often when you strike a hard object it may bend one blade towards the other and this will cause vibration. We can check props for balance and if bent we will send it to a specialist for repair.
Do you know if your boat engine is vibrating?
You know you never hit bottom, but suddenly hatch hinges clatter while underway, and a tingle starts in your feet and travels all the way through your spine. Jeff Fay, owner of Fay’s Boat Yard on New Hampshire’s Lake Winnipesaukee explains how to track down inboard engine vibrations so they don’t rattle your soul. First, don’t overlook the prop.
Why does the prop vibrate when I hit something?
The prop should be balanced to prevent vibration but often when you strike a hard object it may bend one blade towards the other and this will cause vibration. We can check props for balance and if bent we will send it to a specialist for repair.
What would cause a boat motor to vibrate?
Damaged, Loose, or Obstructed Propeller One of the primary causes of outboard engine vibration is a damaged or compromised propeller. A characteristic sign that your propeller is the source of your problem is if throttling to higher RPMs intensifies the vibration.
How do I lower my boat vibration?
Make sure your engine is not resonating and is secured properly to the hull. Your engine mounts are designed to isolate engine vibration from the hull. Engine room should be well insulated. Acoustical insulation helps reduce sound most effectively.
Will a damaged prop cause vibration?
When you run your boat with a bent blade on the propeller, you could cause significant harm to the gearing within the lower unit. Other common issues that come with a damaged propeller include: Vibrations in the drive line. Loss of power and performance.
What would the cause of vibration in propeller shaft?
Vibration in a driveshaft can be caused by many conditions. One of the most common cause of driveline vibration are worn U-joints or slip splines, out-of-balance components, yokes out of phase or misaligned angles, approaching critical speed range, and yoke ears that are not concentric with the splines.
Do boats vibrate?
All boats vibrate to some extent when they're underway, and over time, you, the owner, will become attuned to your particular boat's characteristics. But if you become aware of something new, or it just does not feel (or sound) right, then it may be time to carry out some investigative work to find the culprit.
What causes a motor to vibrate?
Vibration can be caused by one or more factors at any given time, the most common being imbalance, misalignment, wear and looseness. Imbalance - A "heavy spot" in a rotating component will cause vibration when the unbalanced weight rotates around the machine's axis, creating a centrifugal force.
How do I know if my prop shaft is bent?
Check the shaft too. “If the tip of a propeller blade is bent over, there is a good chance the shaft is bent,” Fay says. Place a dial indicator at the taper and rotate the shaft, looking for no more than two-thousandths of wobble. Check long shafts in the middle too for no more than five-thousandths variance.
How do you stop an aluminum boat from vibrating?
But how do you do it? The quickest methods for making a boat quiet include installing soundproofing and or sound dampening materials into the boat's cowling. Materials including rubber (self-adhesive or non-adhesive) and anti-vibration membrane in addition to aluminum layer are highly advisable.
How do I know if my prop is bad?
10 Signs You Should Replace Your Boat PropellerDecreased Fuel Efficiency. ... Too Much Pitch. ... Not Enough Pitch. ... Your Boat Seems Slower. ... Incorrect Diameter. ... Damaged in the Water. ... Blades Are Too Thin. ... Compromise Propeller.More items...•
Will a bent prop shaft cause vibration?
So to answer one of you questions, yes a slight bend in the prop will cause a bad vibration.
How much does it cost to repair a boat prop?
Boat Propeller Repair A typical repair to an aluminum prop will cost $100 to $150, but expect to pay $200 to $400 to repair a stainless steel prop. It may be more cost-effective to simply replace a damaged aluminum prop, but when a new stainless prop costs $400 to $700, the repair makes economic sense.
How do I stop my drive shaft from vibrating?
If it's a used driveshaft that is causing the vibration, sometimes an easy fix is to rotate the driveshaft 180 degrees in the differential yoke. This may help improve the balance. Of course, the universal joints and the driveshaft itself need to be closely inspected, looking for any wear or collision damage.
What does an unbalanced driveshaft feel like?
Loose U-joints or bad center bearings within the driveshaft can cause a worrisome shuddering as you accelerate. This may also be accompanied by unusual sounds. If the car or truck feels like it's faltering or shuddering when you press the gas, take it in to have the driveshaft checked.
At what speed does a driveshaft vibrate?
These are typically felt at lower speeds, from 0 to about 40 mph. These are also worse on heavy throttle and load, when accelerating or going uphill. Angle related vibrations are often described as a shudder and usually get better or go away when you let off the gas or shift into neutral.
How do I stop my boat from vibrating Xtend?
Swipe Up on the home screen of the watch. Click on the DND button. It will not vibrate for any calls or notifications until you turn the DND mode off.
Which of the following main source of vibration aboard a ship?
The moving parts of the diesel engine act as a primary source of excitation for whirling. The grass pressures in the engine act as exciting forces. The radial components of the gas pressure are responsible for the whirling vibrations, whereas, the tangential components are responsible for torsional vibration.
Why does my outboard shake at idle?
A rough idle on an outboard is generally caused by a failed spark plug, a clogged or stuck open fuel injector, a clogged or dirty carburetor, or an engine that has an issue with the timing when dealing with a 2-stroke outboard.
How do I stop my motor from vibrating?
An easy method to reduce vibration is to install a clean damper on the rear shaft of the motor. Clean dampers are basically hermetically sealed plastic cases with an inertia body packed with silicon gel. The extra inertia and silicon gel help absorb the vibration and provides a stable damping effect.
Can too much oil cause engine vibration?
Too Much Engine Oil As it spins, foam and bubbles accumulate around your crankshaft, hindering the oil from properly lubricating your engine's internal components. If your engine's internals isn't adequately lubricated, friction can develop, resulting in noticeable engine vibrations and shaking.
How do you check engine vibration?
1:265:54Vibration Analysis for beginners 2 (how to start your Predictive ...YouTubeStart of suggested clipEnd of suggested clipWhere you place the vibration sensor and where you take your vibration measurement the measurementMoreWhere you place the vibration sensor and where you take your vibration measurement the measurement point location must enable you to take repeatable measurements under the same conditions.
Which part of a propeller blade is most susceptible to vibration damage?
Metal prop blades are especially susceptible to destructive vibration if they are excited near a resonant frequency. One reason is that a metal blade contains very little internal damping, so resonant vibrations can build in amplitude very quickly.
What can be determined when a propeller hub appears to swing in a slight orbit?
If the propeller hub appears to swing in a slight orbit, the vibration is usually caused by the propeller. If the propeller hub does not appear to rotate in an orbit, the difficulty is probably caused by engine vibration.
How do you use a universal propeller protractor?
1:364:22Prop protractor - YouTubeYouTubeStart of suggested clipEnd of suggested clipYou must first zero it by locking the inner ring and the outer ring together using the inner ring.MoreYou must first zero it by locking the inner ring and the outer ring together using the inner ring. Lock. Then unlock the inner ring.
Why should a prop be balanced?
The prop should be balanced to prevent vibration but often when you strike a hard object it may bend one blade towards the other and this will cause vibration. We can check props for balance and if bent we will send it to a specialist for repair.
Why is the log gland rubber loose?
The log gland rubber can be loose at this time as to not put pressure on the prop shaft.
Do you need to tighten the coupling on a prop shaft?
The Prop shaft coupling must be tight on the prop shaft for motor alignment . When you remove the coupling bolts to the drive and you find it is loose on the prop shaft then most likely it is time to replace as all types of couplings should be tight when fitted to the shaft prior to tightening the bolts or cap screws.
Why does my boat have vibrations?
Often, the source of onboard vibration can be traced to problems with the engine and running gear. This guide is designed to help you track down and hopefully correct any problems in that arena. Because the parts in the drive train and running gear are interconnected, something that is worn or out of alignment puts extra stress on other components that may also suffer.
How to tell if boat shaft is worn?
When the boat isn't running, you can run your finger around the shaft where it enters the stuffing box and see if you can feel any wear, which could indicate an excessively worn shaft, a potential cause of shake and vibration .
How to tell if a prop shaft is loose?
There should be zero fore and aft movement , which would be indicative of either a loose prop, a loose prop shaft coupling, or wear in the transmission.
What to inspect propeller for?
Inspect propeller for rope, fishing line, weeds, or other fouling.
What happens if shaft turns easily?
Disconnect shaft from transmission. If shaft then turns easily, alignment issue is likely.
How to check sailboat props?
Check prop with a dial gauge to ensure it is in round. On a sailboat with folding props, make sure that the blades open and seat correctly.
What to do if propeller is damaged?
Remedy: Repair or replace the damaged propeller.
Why does my boat have a vibration?
Vibration can be caused by a number of problems, all of which require immediate repair work. So if you sense that your engine is rattling around too much, you should not ignore the problem.
What happens if an outboard engine vibrates?
As well as being very unpleasant for everyone on board, if left unattended, this vibration could cause severe damage to the integrity of the hull. If your outboard engine is vibrating, you should inspect the condition of the engine mount.
How do outboard motors work?
Instead, the engine on your vessel is attached using an engine mounting. The engine mounting is bolted to the hull of the boat and forms a kind of cradle in which the outboard motor sits. The mounting is fitted with flexible rubber strips which help to absorb the vibrations created when the engine is running. However, when exposed to water for an extended period of time, the attachments which connect the mount to the hull and the shock absorbing strips can begin to fail. When a failure of these two components occurs, it can lead to excessive vibration which seems to travel through the hull of your boat. As well as being very unpleasant for everyone on board, if left unattended, this vibration could cause severe damage to the integrity of the hull. If your outboard engine is vibrating, you should inspect the condition of the engine mount. If you find any signs of damage, you should take the boat and mount to a boat mechanic who will be able to advise you if you need to repair or replace the component.
What happens when you expose a boat to water?
However, when exposed to water for an extended period of time, the attachments which connect the mount to the hull and the shock absorbing strips can begin to fail. When a failure of these two components occurs, it can lead to excessive vibration which seems to travel through the hull of your boat.
Why do boats spin?
The spinning creates large centrifugal forces. Propellers are finely engineered and balanced so that this energy is dissipated into the surrounding water.
What happens if a propeller is damaged?
However, if one of the propellers on your vessel is damaged, the additional drag it creates as it passes through the water can cause it to become unbalanced. When you get back to base, you should carry out a visual inspection of the propeller. If a blade is misshapen, you should replace it with a new blade.
How to test a jiggery drive shaft?
Take no notice of jiggery pockery. There is a simple test. Remove the coupling from shaft to gear box. Push the shaft back a bit. Get a local engineer to make you a collar, which fits snuggly over your gear box drive shaft, with say three inch remaining.. Now pull the shaft back, it will fit into the collar, or it wont. Many have tried other ways, but resorted to this, the shaft should glide straight in.
Does vibration affect water speed?
Whatever the source of vibration, it's very unlikely to be related to the water flow speed, which is the only thing which really changes between cruising at any given rpm with one or two engines.
Do cutlass bearings give low speed vibration?
have you checked the cutlass bearings recently? these can give low speed vibration that goes away with speed
A Case of the Shakes
Being out on the water presents a wonderful opportunity to de-stress, but too much vibration can shake your hardware loose and detract from your enjoyment.
First Things First
Before going down the rabbit hole of vibration mysteries, start by having a mechanic come on board for a test run. Boat owners can become desensitized to sound and vibration, and a technician with trained eyes and ears can uncover problems that an owner may not recognize.
Propellers
After hauling the boat, the hunt for the culprit begins with an inspection of the prop. Before messing with the drivetrain, you need to eliminate the prop as a suspect. The most conclusive diagnosis involves removing the prop and sending it out for a digital scan.
The Shaft
A shaft can cause vibration in one of two ways. First, the shaft might be bent, either as a result of impact to the propeller, or because of mishandling during shipment or installation.
Engine Mounts
Motor mounts are basically two metal plates with rubber between them. The plates are sometimes formed so that if the rubber fails, the two pieces of metal will remain attached. Engine manufacturers use different durometer rubbers (sometimes on the same engine) to isolate the normal engine vibration from the engine stringers.
Alignment
The shaft must align to the engine within very tight tolerances. A collar (referred to as the “coupling”) fits on the forward end of the shaft and bolts to a flange on the transmission. A coupling is a precisely machined steel component that transfers the rotational energy of the transmission to the shaft.
Transmissions
There is a device between the engine and transmission that reduces the shock loads of shifting. This device is called a damper plate. It is in the bell housing between the engine and transmission. It utilizes either springs or rubber for mitigation, and once that material wears out or breaks, the damper plate can make an awful racket.
What happens if a prop is out of balance?
What you describe on this prop it has to be out of balance and out of balance will cause vibration. The flat spotted blade and the nicked blades will all have different pressures on them in the water which would cause a vibration , another imbalance problem. Take it to a prop shop and get them to repair it.
Where is the pitch stamped on a Merc prop?
A Merc prop will have the part number and the pitch stamped in the prop housing between the blades. If you decide to replace the prop there is no better place than Iboats to buy from, you can also check on their exchange program, you buy one prop,try it and if it is not right they exchange it for a different one.
Can a bad prop cause vibration?
Yes, a bad prop can cause vibration.
How to tell if boat shaft and engine are parallel?
Push a feeler gauge between the coupling faces — if the gap is tight at 3 o’clock and looser at 9 o’clock, or vice versa, the engine and shaft aren’t parallel in the boat.
How to tell if a propeller blade is bent?
Check the shaft too. “If the tip of a propeller blade is bent over, there is a good chance the shaft is bent,” Fay says. Place a dial indicator at the taper and rotate the shaft, looking for no more than two-thousandths of wobble. Check long shafts in the middle too for no more than five-thousandths variance.
What is the adjustment of the motor mounts?
Motor mounts adjust too. A coarse adjustment left to right ensures the engine and shaft are parallel port to starboard and the shaft is centered to the engine.
Does a vibration absorbing coupling insert smooth out a rattle?
Added Flexibility: As a last resort, Fay says, a vibration-absorbing coupling insert might smooth out an otherwise rattle-prone drivetrain. Just be sure the propeller still clears the rudder once it’s pushed aft by the insert’s thickness.
What happens when a prop is tuned?
A prop is tuned and pitched like an instrument. If a blade is slightly out of true, it will send vibrations. Some are undetectable, whereas others will be felt in the steering wheel or with your feet on the deck. Although the vibrations may fade as speed increases or decreases, harmonics are still in play.
Does wakeboard feel smooth?
Everything felt smooth at wakeboard speeds and even idling, it was just on initial acceleration it was a very noticeable rattle, even could hear rattle at the helm.
Can a bent prop cause vibration?
A bent prop will cause vibration throughout the boat usually, though of course its worth looking at since the exact loaction of helm vibration can be misleading. An issue in the steering system however will manifest itself in the wheel. My suggestion is this, on a 2008 you have a rudder trim tab. Move it some.
