May 2018

Some years ago a chap who later became a good friend bought a Rocket 3 with a "rebuilt" engine.

Within a few hundred miles it became obvious that things were not all hunky-dory within, and that led to another chap removing head and barrels.

A total strip was then arranged, but for reasons it never happened and the engine sat at the second address until recently when it came to me.

Whilst the cylinders were on max oversize at +.040 the pistons were in good shape as were the bores, so it did not seem that any of the smoke or mechanical noises were coming from there. Careful studying of the pistons did suggest that one conrod was slightly bent however.

The crankshaft had a tightness that was immediately cured by removing the drive side main bearing shell. The bearing had worn badly in the brief mileage so was possibly on a journal that had not been ground correctly down to what was now -.040 and the minumum undersize.

Every mating surface was liberally coated with a very tenacious sealant, plus many bolts were glued in, plus there was liberal use of araldite and knead-it on broken threaded bosses.

Here are some photos of various engine parts that were revealed before I stopped progress completely.

A nicely modded bolt from primary side

Outer primary cover

Inner primary cover


Clutch cover

Drive side crankcase

Timing cover

Tming side crankcase

Every cover removed revealed more butchery, so I have stopped at this point while the owner decides what to do.

At considerable cost the alloy bits could be welded up and repaired, but the full extent of the carnage may also prove that many engine components are not reusable.

I seriously doubt that I could ever assemble this engine and feel confident in the outcome.

While I have heard the horror stories, this is the first experience for me of such total butchery.

Real shame.

This engine job resumed in January 2020 so has another page further down.