January 30, 201016 yr Hi, Just had a look at the underside of the crank cases and I am not sure if they are 100% ok. On the gearbox drain plug side there is a ridge (crack?) that apears perfectly straight for about 1"then turns perfect 90 degrees and runs for another 1". In the center of cases ( where the casting has a hole running back up into it on about a 45 deg angle) there is a similar ride. Could they be casting marks or has something gone a bit wrong at some time. Photos of some in good condition would be appreciated, Cheers
February 1, 201016 yr Hi I have got exactly the same lines on my M80 crankcases. They are simply the die/mould break lines so that the cast crankcase can be removed from the die once cooled. They are located by the redundant speedo drive and drain plug. I suspect there were pins in the tooling to form a holes prior to drilling out and tapping the finished spec. If you look at an Airfix kit you will always see the tooling lines as well as ejector pin marks. Hope this helps. Martin
February 2, 201016 yr Author Cheers, thanks for help, spot on as usual. I can build top end back up now with no worries.
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