Chunk missing from 850 barrel

... after one of the oil pipes came off the filter and the n/s big end locked solid, snapping the rod and taking a chuck out of the bottom of the barrel. This was about 40-odd years ago and happened about 3 weeks before we were due to go to Germany on the bike. The missing chunk was (from memory) about 1 inch wide by 1/2 high. I asked at a local engine reconditioning place and they suggested that as the damage was below the rings if I dressed it with a file so the was no sharp edge it would be OK.

I did this and with a reground crank, new con rod etc it made the trip without incident (apart from oil leaking from a cylinder head stud) and gave good service for the following 2 years till it was stolen.

Yeah, one of mine suffered similar damage when I threw a rod. Liner fittted and never encountered any problems - standard bore. It was once suggested that there might be a risk of the liner rotating in the barrel which would move the cutouts for the conrod out of line. But, as I say, never any problems. Not sure where that barrel is today.

On the other hand, if you're on +060 maybe it's time for a new barrel and pistons.

Yes, you can fit a liner to an 850 barrel, there is a big but. Look at a liner wall thickness and you'll see that it is not wise to take out to +60. If you really need to fit a liner then fit to both sides and keep to standard bores. 

As Ashley says, if you fit a liner, don't bore it out. That way future extreme expense lies. 

... people are wealthier these days than I was back then. My parsimonious habits still persist however and I'm always surprised how many people have rebores, crank grinds etc when existing components are still well within useable limits. My bible is my dad's 1948 copy of "The Motorcyclist's Workshop", particularly the chapter entitled "Is it worn out?"

Good excuse to go 920?