| February/March 1989

Over the past thirty years that this writer has been involved with vintage engines, one of the most vexing problems is that of a troublesome igniter. The problems almost always have their root in excessive wear of some parts, improper springs, and worn trip mechanisms.

Stover was one of the first builders to use an outboard bearing on the igniter shaft-this eliminated most of the problems with the igniter shaft binding in the body and causing sluggish action. Some builders weren't very careful about the type of seat they used on the moveable igniter shaft either, so that before long there was considerable compression leak-age past the shaft. This eventually loaded the shaft with carbon deposits, making the shaft work poorly if at all.

If there is compression leakage past the igniter shaft, then it may be necessary to re-machine the shaft back to its original dimensions. This will probably necessitate the addition of weld or bronze to the low spots. After returning the shaft to its original specs, then go to work on the hole-it may require that you bore it out and install a small sleeve of the proper size. After all this, it will be necessary to grind the seat on the igniter shaft to the seat on the inside of the igniter body. Many times this can be achieved by lapping, but occasionally it is possible to do at least a portion of the work in the lathe, saving an awful lot of hand work. Regardless of the methods used, the igniter shaft should have no appreciable play, but must have no drag at all-it has to be free! Furthermore, the mating faces of the igniter shaft and the inside of the igniter body must be absolutely gas-tight. This can be determined by pouring some gas onto the joint. If there is no leakage, the gas will remain there. Usually the return spring on the igniter has a fairly open wrap so that it can also function as a compression spring. It will exert a slight outward force on the igniter shaft, thus holding it tightly to its seat.

24/2/1 Bull Pup engine

Q. I would like to correspond with anyone owning a Bull Pup engine, 1? HP built by Bates & Edmonds Motor Company, and sold by Fairbanks Company. Joe Morris, 112 Irwin Road, Powell, TN 37849.

24/2/2 Monitor engine