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- Aug 25, 2007
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This, strictly speaking isn't a new project. I started this Hit n Miss engine in the mid 90's and finally got it running in the early 2000's. It started out as a copy of Phil Duclose's Odds n Ends engine, but I departed pretty radically from his design on the cylinder assembly, building it up out of a cast iron sleeve, a piece of thin walled steel tubing, adding a head and valves of my own design. The engine has never run very satisfactorily, starting hard, running too fast, and not wanting to run at a nice, slow pace.
Over the past few years I've done things which have helped. I added more weight to the flywheels by pressing a quarter inch thick steel ring cut from pipe over the existing flywheel rims. I've also modified the carburetor, reducing the internal diameter from 1/4" down to 3/16". Finally, I removed several turns from the intake valve spring so it will just barely hold the valve closed between intake strokes.
This weekend, I'm going to shorten the connecting rod, lowering the compression ratio. And, I'm going to make a new piston which fits just a little looser than the existing piston. If anyone has any other suggestions, I would appreciate any input. I will take a video on Sunday after I've completed the remaining work.
Over the past few years I've done things which have helped. I added more weight to the flywheels by pressing a quarter inch thick steel ring cut from pipe over the existing flywheel rims. I've also modified the carburetor, reducing the internal diameter from 1/4" down to 3/16". Finally, I removed several turns from the intake valve spring so it will just barely hold the valve closed between intake strokes.
This weekend, I'm going to shorten the connecting rod, lowering the compression ratio. And, I'm going to make a new piston which fits just a little looser than the existing piston. If anyone has any other suggestions, I would appreciate any input. I will take a video on Sunday after I've completed the remaining work.