Over the last several years I have seen many logbook entries from mechanics, some good, some bad and some just downright ugly. In the last several weeks I have been involved with a buyer looking for a used Flight Design CT ($70K - $90K). This has given me a unique opportunity to really look at logbook entries and documentation (or the lack of it) and see just how that might affect the ultimate selling price of the aircraft itself. Surprisingly, many poor entries have also come from A&P’s and not only RLSM-A’s from the logbook entries I have seen. These poor logbook entries and lack of documentation will cost the owner dearly when it comes time to sell. From what I have seen lately, it’s not hard to lose $5K-$10K in value due to lack of documentation. These are legal records and need to be treated as such. This is one of the only legal ways you can show either someone did something to your plane or did not. As important, log books showing compliance to not only the aircraft manufactures Service Bulletins for the airframe but also for its Rotax engine greatly increases the Aircrafts total value!

There is a right and wrong way to install spark plugs on your Rotax 912 series engine.

First, we need to use the proper plug, so make sure you have the proper numbered plug. Don’t take it for granted they are all the same, stop and look at each one. It’s imperative that they are uniformly identical in the number. Using the wrong plugs will, inevitably lead to problems, so be alert.

For example, the 912UL (80 hp) uses an NGK DCPR7E and the 912ULS (100 hp) uses the NGK DCPR8E. The correct gap for these is .023 - .027. The packaged plugs will usually have a wider gap and will need to be re-gapped. It’s better for you run a wider gap during the summer, and the smaller gap during the colder winter, your starts and over-all running will be better.

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