Wit­ness Marks Steve Zim­mer­man

Passage Maker - - Contents - BY STEVE ZIM­MER­MAN

This Flem­ing 58 high­lights sev­eral best prac­tices. The ma­chine screws and nuts that se­cure the engine mounts in place must not move and loosen de­spite engine vi­bra­tion and tem­per­a­ture vari­a­tions. Lock­ing wash­ers have been in­stalled, and once prop­erly torqued, a yel­low wit­ness mark has been ap­plied. Any fas­tener rotation will dis­place the yel­low marker, high­light­ing a prob­lem.

The engine mounts have been shimmed, or raised up above the supporting struc­ture. The shim has been care­fully ma­chined from stain­less steel, with am­ple radii and fil­lets to elim­i­nate any sharp cor­ners that can be­come stress con­cen­tra­tions. Engine-mount shims should al­ways be fab­ri­cated from a ma­te­rial that will not com­press un­der the weight of the engine.

The black gen­er­a­tor fuel hose on the lower right has been se­cured with a P-clip to pre­vent it from chaf­ing on the edge of the oil-change pump. Just above the hose you can see a neat bun­dle of green 8-gauge wire for the bond­ing sys­tem. Bond­ing sys­tem wires must not be daisy­chained from one fit­ting to the next—a prac­tice that cre­ates cu­mu­la­tive re­sis­tance in the cir­cuit. The bun­dle shows wires from each un­der­wa­ter com­po­nent con­nect­ing to a main bond­ing strap. One small area of fo­cus, but many ex­am­ples of the Right Stuff.

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