JIMS Machining Twin Cam Engine and Trans Plug Kit - Tool Time

Enough caps and plugs to fill an engine.

JIMS Machining Twin Cam Engine and Trans Plug Kit - Tool Time

JIMS Machining Twin Cam Engine and Trans Plug Kit - Tool Time

I have no documentation to back this up, but I think it’s safe to assume that many more Harley-Davidson owners perform some level of engine work on their bikes than do owners of any other brand. After all, millions of Harleys have been sold over the years, a large percentage of which are still out there in one form or another, and they haven’t changed in basic design as much as other bikes have. On top of all that, the relative simplicity of H-D engines encourages owners to tackle major motor repairs and modifications themselves.

For the most part, that’s a good thing. But one of the mistakes I’ve seen home mechanics make far too often is a failure to keep contamination out of the engine. They tend to leave all of the many orifices, large and small, uncovered either while they’re working on another part of the engine or while it is stored awaiting parts or completion. Insects can then crawl unnoticed into small orifices, and dirt or other more-damaging debris can find its way into any of the openings, regardless of size. The end result can range from no harm whatsover to a problem that ultimately leads to yet another disassembly and repair.

For owners of '99-to-present Twin Cam Harleys, JIMS Machining (www.jimsusa.com) offers a practical solution with its Twin Cam Engine and Trans Plug Kit (part #764, $64). It's a 55-piece collection of enough caps and plugs to seal off every opening and orifice on any Twin Cam engine and transmission from Dyna to Softail to FL. The kit's two large foam plugs have square holes cut through the middle so they can slip over a connecting rod and into the cylinder opening to prevent anything from accidentally falling into the crankcase. Smaller foam circles effectively close off intake and exhaust ports. An assortment of rubber and plastic caps is used for lifter bores and all of a TC engine's numerous oil passages, and there even are some small rubber plugs that block off the oil lines themselves. Instructions explain which plug goes where, and everything stores nicely in an included clear plastic box.

Yeah, 64 bucks might seem a bit steep for a box of foam and plastic circles. But using them is a much more professional approach than stuffing a disassembled engine’s critical openings with rags and newspaper—or with nothing at all.