Technical Tips

CONNECTING ROD SIZES

The sizing chart below shows the safest way to know the actual size of the connecting rod, if standard or undersize, far more accurate than a vernier caliper. Ideal for parts suppliers and plant hire workshops etc.

The above can be turned out from mild steel or aluminium.

HOFFMANN WATEER PUMPS PRE-DELIVERY CHECKS

Sometimes it can be difficult to start an engine. This may be due to insufficient fuel or incorrect engine bleeding. Sometimes people use Quick Start to start an engine easily, but be warned - the use of

Quick Start can cause severe damage to the ring lands on the piston as can be seen in the photo opposite.

The warranty on this engine became invalid, despite the fact that it may only be two months old and had done little work, due to the damage done to the ring lands by the incorrect application of Quick Start.

If it is necessary to apply Quick Start, make sure you know what you are doing.

HOFFMANN WATER PUMPS PRE-DELIVERY CHECKS

1. Before delivery, Hoffmann carries out the following checks to all new Hoffmann Water Pumps:

• Pre-delivery inspection

• Pressure checked and tested up to 70 kPa

2. Hoffmann adopts the same procedure when undertaking repairs to water pumps.

All tests done in the Hoffmann workshop are accurate – you can be sure no guesswork is involved.

Jeff Eldon Technical at HOFFMANN

ALWAYS REMEMBER

Tight tappets will be the cause of burnt valves. Tappets with too much clearance will result in early wear to rocker arms and push rods.

SMALL PETROL AND DIESEL ENGINES

Valve clearance should be checked for the first time after 50 hours or one month set at 0.025 when hot. Thereafter every 400 hours or six months.

HOW DO I PREVENT MOISTURE FROM ENTERING THE CYLINDER?

4 STROKE ENGINES - PETROL OR DIESEL

Always remember after stopping the engine on your genset or water pump, or any other engine driven unit, to pull on the recoil starter until compression is felt. This will mean that both valves are in a closed position, which will prevent condensation or moisture from entering the cylinder. Dampness can cause sticky valves and therefore starting difficulties.

This is very important for lawnmowers that have not been used for long periods during winter and engines at the coast.

CHOOSING NOZZLES AND PRESSURE CLEANER TIPS

For using pressure washer efficiently you need to choose the correct nozzle and tip. The majority of our machines come with interchangeable spray tips that serve two purposes. One is to lower the pressure and draw the detergent; and the other is for high pressure rinse at the different spray angles.

Our pressure washers come with several color-coded tips/nozzles (red, yellow, green, and white) that vary from 0 degrees to 40 degrees. As a general rule the smallest angle delivers the most powerful "punch." For example, it you want to remove a stubborn smudge from you driveway you will use a 0 degree angle.

However, if you want to move debris (such as leaves, sand, etc.) away from your house you will use a wider angle such as 25 or 45 degree nozzle. Caution: be sure the nozzle/tip is completely attached before using the trigger gun. Failure to do so may result in the tip becoming the projectile and may be lost or it may damage the property and/or harm persons.

WHAT CHEMICALS CAN BE USED?

Use only cleaning solutions that are power washer approved. On our pressure-washer-chemicals page you will find sufficient solutions that are safe for your machine, plus they are biodegradable and environmentally friendly.

WHAT IS POWER WASHING?

Power washing, or pressure washing, is the growing application of high pressure water spray. Produced by specially designed pumps, this spray is a hundred times more powerful than the typical garden hose. On concrete it is used to remove unsightly mold, bubble gum, and other dirt stains. Wooden decks are returned to the look of new wood, void of graying and fatigued finishes. And on houses, the appearance of siding (namely aluminum and vinyl) is greatly improved by removing pollution, mildew, and other signs of neglect.

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