You need to refer to the owner's repair and maintenance manual to know the proper sequence for the settings of a motorcycle. Usually, these information are found in the first few pages. I strongly recommend you to read the entire section and get familiar with the periodical chart. Very few owners actually take the time to read it. Yet, there are multiple engine types and countless differences between all of them.

Today, I will essentially focus on valve settings for single- and multi-cylinder engines. Over the upcoming weeks, other settings will be featured and explained.

Before going any further, I'd like to warn those who don't possess a deep knowledge of mechanics -- please, let a skilled and experienced technician work on your bike.


THE VALVES
Part One

Settings work by using various systems: rockers, worm screws and locknuts, shims or hydraulic levers (arms). The latter require no maintenance or adjustments (except for a reworked engine), so I won't talk about it.

You need to have the proper tools depending on the type of powerplant found on your motorcycle. Feeler gauges -- and, possibly, special wrenches -- are necessary in the case of rockers with worm screws and nuts. You can get them at most motorcycle parts retailers. A good idea is to browse through the parts & accessories section of their websites.

Having to replace core plugs on an engine can be quite expensive. Furthermore, this maintenance work demands more time and knowledge.

Adjusting the settings on a SOHC or DOHC engine with rockers and worm screws requires the same basic technique. It's reasonably easy to perform, provided that you understand how your engine works exactly. The first step is to set cylinder # 1 at its top dead center, in the case of a multi-cylinder unit like an inline four-banger. On most Japanese bikes, you'll find markers on the cams which will help you make sure that the piston is positioned at the highest point of its stroke. Be careful: you must comply with the rotating direction of the engine; some internal parts might break when rotating in the opposite direction.