STARTERS AND ALTERNATORS

Inertia starter
An inertia starter motor works by throwing the pinion into mesh with the fly wheel at high speeds causing the engine to turn over. this is achieved by electrical current flowing through the magnetic shoes causing the armature to spin which then throw the pinion into gear. Once the pinion has forced the fly wheel into rotation the side of drive would change, making the pinion clutch engage retracting the pinion.

Pre-engaged starter
This starter works and relys on the solinoid which uses a lever/linkage to enguage the pinion before it starts to spin, this system means that there is minimum wear on the teeth.

Alernator
An alternator is an electromagnetic unit that is driven by a belt from the motor this means it wont run under its oun power. This is a rotor that cuts the magnet feild made by the coil and shoes, it turns within a stationary set of conductors called a stator. As the rotor is driven it cuts through the magnetic field causing the current to change producing an alternating current. This current changes due to the different polarity of each side of the magnet. This current is then feed through a rectifier which stabilises the voltage to a direct(DC) current. The alternator is used to power the electrical systems of the engine once started and charge the battery so it produces around 14 + V

BUISNESS PRACTICE

Warranties
When you buy a product e.g. an outboard it may come with a description of what it will do for how long but in the fine print it might say you have to run the engine on non synthetic oil and stay under 5000 revs and to flush it out for 7 minutes minimum. it is important to read all of the small print because a warrant is a legal document that assures you that it is going to work properly.

Guaranties
a guarantee is what the name is - if you buy a new part or have a new part installed professionally, the workmanship and life of the part being installed is usually guaranteed, so if the new part were to fail you wouldn't be expected to pay unless you did something against what the legal warranty said.

Quotations and estimates
A quotation is an agreement between both parties of what the job will cost this can be a range from x to y  but if the final price exceeds this you may be facing legal charges.
An estimate is a rough guess of how much you think the job will cost, this is not a legal bond like a quote so it is important that you make yourself clear to the customer what you are giving them so there is no grey areas.

Charge out rates
when deciding on a charge out rate it is important to take into account your overheads, employers and yourself. All those into consideration a $60 per hour charge out rate is not so steep.

Courtesy arrangements
these can be anything from cleaning the inside and outside of the car, checking tyre pressures, cleaning the inside if headlights, giving the customer a ride home (if local) and even offering a temporary car whilst theirs is getting fixed. All are done to keep the business turning over and money coming in.

Cultural issues
Because the world today is not split into races and cultures it is important to accomodate for difficulties, these  refer to expectations, Practises, Communication issues e.g. being clear on the phone etc.

MARINE TRANSMISSIONS

Outboard gear box
This system runs from a pinion wheel directly from the engine which turns 2 gears at the same time, however only one is ever engaged and driving (under power) by way of a dog clutch.
The gears are selected by a selector rod which has a slot on a slant that moves the dog (that is fixed to the prop shaft) into the desired forward or reverse gear.
the gears are helical tapered gears which run directly onto the prop shaft.

Stern leg system
Unlike the outboard gearbox the stern leg transmission is vertically positioned on the shaft that drives the prop shaft. The clutch system unlike the outboard dog with teeth the stern leg clutch is a tapered system that will engage either forward or reverse depending on the position of the selector shaft.
At the end of the drive shaft where the prop shaft joins is a pinion wheel and one or two permanently engaged gears - if the engine is duo prop or single props.

Inboard gearbox
An inboard gearbox uses hydraulic fluid to compress a clutch pack which therefor engages the prop to move forwards or backwards. The concept of this system is much like a motorbikes.

What type of gears are used in stern legs and outboards?
tapered helical cut gears are used in outboards and stern legs because the offer the best contact between teeth all the time especially on the pinion - this type of gear also reduces noise.

The duo prop system
This works by having a pinion drive and two constant mesh gears rotating in opposite directions and moving one shaft inside the other. a propeller is fixed to each of the shafts which are rotating in different directions, this means that one of the propels has to be cut counter rotational drive so the engines props are always moving the boat the same way whilst the props are not.

The "V" drive system.
this gear box is to change the direction of the drive shaft, it also enables you to focus the majority of the engines weight further back in the boat. it does this through 2 stages in the gear box
1. the drive shaft enters the gear box and drives the first stage which is 2 shafts the first one is the one that the drive shaft is turning, it has straight cut teeth that drive a chain that turns the next shaft which also as well as having the straight cut teeth and chain linkage, has a tapered helical cut gear on the end of it so it acts like a pinion.
2. the second shaft drives the output or third shaft on the helical cut tapered gear - allowing for the change in direction.

Jet unit and Surface drive.
A jet unit has a water intake on the bottom of the boat, the water is then pushed through a prop in the tube causing the water to exit under very high pressure (enough to push a boat). this type of drive is very effective if you are going over shallow sand bars or shallow rivers etc.
A jet unit is especially good at turning this is achieved by moving a cap over the water out put and directing it  to where ever you want without loosing power, this is why a jet boat can turn almost 180 degrees without moving.
The downside to a jet boat is that you have to be under power to maneuver the boat otherwise you will just drift.
A surface drive works on the theory that the more you have in the water the more drag you have and the slower you will go. a surface drive always has one blade out of the water at any time, this is so you accelerate faster, there is less drag and you use less fuel.