Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Have struck gold in finding a very nearby SOHC Engine guru, who’s been building, modifying, racing the ‘750 unit (sidecars) since 1972. And extremely generous with his time / knowledge; I traipse up-to his workshop with bits in hand, and rattle through things that would otherwise take me days … if I even knew to do them.Anyways, yesterday, Lindsay cleaned out the four oil galleries within the crankshaft. (I was convinced this was a waste of time as I’d bathed it 48hrs in degreaser, and then pressure washed those galleries with a garden hose….)First up he TIG welded blobs of steel onto the ball bearing plugs, before tapping them out with a cold chisel. This gave us access to the gallery downstream of the big end ports…. which were truly blocked with **it. (same workings as a centrifugal oil filter I guess). With a 6mm(?) drill bit this was all removed to a depth of about 1”… ie the bit broke through more-or-less at the big-end oil ports. (The crap that came out was a plastercine like sludge)Then a wash out, blow dry… replace with a new ball bearing using the original punch marks to secure. (The top photo shows the gallery path depicted with the screwdriver. The con-rods have been reinstalled and so the big-end oil ports not visible in the pics)May not impress the established engine builders here - but this was all new to me.
Your wrong Simon, that impressed me. Never heard of anyone doing that before, great info and might explain those unexplained "why has my engine seized" questions when there is no rational explanation, a big clump of that stuff coming loose would ruin most engines, who knows what it contains.