Peter Rooke tackles a tough IHC restoration project – Part 2

| February 2008


Peter Rooke’s latest project, a 3 HP IHC Model M.

Editor's note: Last issue, we began a three-part feature on Peter Rooke's latest restoration project. We continue below with Part 2.

Fuel mixer

Like most fittings on this rusted engine, the fuel mixer needed considerable attention.

It was necessary to give the body of the mixer a good clean with a wire brush and all brass fittings were also removed. The fuel reservoir was cleaned using kerosene and a small toothbrush. The screw to hold the choke cover broke when I tried to remove it, so I drilled the remainder then use a tap to re-cut the thread.

The lever on the tap to control/empty the fuel reservoir had long since rusted away, making it difficult to remove the tapered shaft. While it is possible to heat the shaft to pop it out, I do not like using heat on cast iron unless I have no other option. An alternative is to drill a hole in the base of the casting, using a punch to press the taper out of its seat, then tap the hole and fit a screwed plug to seal it. However, I had to make a new lever for the tap and rather than peen the brass of the body over the new lever to hold it in place, I decided to drill and tap the body for a large head screw. The threaded hole could then be used for a temporary bolt to help pull the shaft out.

Once the body of the tap had been extracted, its seating area was cleaned. The top of the tap was faced off, the remains of the old lever removed, and a new lever was drilled and filed to shape. A brass screw was turned to hold the lever in place and the head made over sized for a very shallow slot that could be filed when the screw was firmly in place.

The needle valves had to be replaced and the state of the valve seats was unknown. Some 5/16-inch brass was turned, then threaded 5/16-by-18-inch and tapered to match the originals. At the same time that the lathe was set up to turn the taper, a piece of steel was machined to copy the brass stems. Later, the steel was used to lap the valve seats with very fine compound so the new valves would be a good fit.