Spark Plugs

1. After a new engine has gone through its run-ning-in period, colder than the original plugs may be needed, especially as concerns O.H.V. Models. The type of plug required depends on compression TStio and how hard engine is driven. This cannot be determined by compression ratio alone, as some high compression engines see very moderate service, and some low compression engines are driven very hard.

2. If, in an engine in average good condition as concerns valve seating, compression, timing, etc., plugs after a short time in service are found with cores blistered, cracked or partially burned away, this indicates the need of either a richer high speed carburetor adjustment or colder plugs. If plugs are found with an accumulation of oily soot or carbon, and possibly fouling difficulty is experienced, this indicates the need of either reduced oil supply or hotter plugs.

In some cases best results may be found using a colder plug in one cylinder than in the other. In this case it is usually the front cylinder that takes 1he colder plug as this cylinder is not as likely to foul plug at low speed. Here's the thing to bear in mind: The colder the plug that can be used without running into fouling difficulties and hard starting, the longer plug life will be and the less chance there is of engine failure and damage from pre-ignition and overheating.

3. The core tip of a plug in hot service will in time, possibly only a short time, acquire a brownish, glassy coating. This oxide coating is a conductor when hot, and will cause missing at high speed or under heavy engine load. Plugs should be cleaned regularly to remove this coating.

4. Do not take plugs apart to clean nor try to save a few cents by installing new core only when a plug has to be renewed. Reassembling without proper equipment for adjusting and testing, runs into a high percentage of failures due to leakage and core cracking. These things very often contribute to serious engine trouble.

The recommended method of cleaning is with a sand-blast cleaner found in nearly every service station.

5. Correct plug gap is .025" to .030". Since gap increases slowly with use due to gradual burning away of electrodes, plugs should be checked and reset occasionally. When regapping, adjust only the base electrode, as bending center electrode will break porcelain core. For high speed service it is well to adjust gap to low limit (.025").

DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

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