920 liners
- Thread starter baz
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RGM seem to think so and recommend thin old skirt sections are removed. See bottom of page 3
baz
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I ask as I have a 920 rgm barrel and I can clearly see the liners
But the bike I recently purchased supposedly has a 920 barrel
But there are no signs of liners looking through the fins ?
Fast Eddie
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The castings can vary IFAIK and sometimes the liners are visible and sometimes they are not…
baz
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Ok
Looks like I may have to pull the head at some point to check
I'm told it's bored to 920 with virtually no miles on it
Hasn't run for two years so I'll take it easy if/when it starts
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Castings are somewhat a black art, the practical tolerances are large so yes you will get some castings that will be machined out into fresh air in sections when bored for 920 and others that show no signs. With such large variations the other black art was where to take the first datum cut so the subsequent cuts did not scrap the casting. All while the buyer was telling the casting maker they were casting them too heavy and the price was too high and to save some weight and cost.
marshg246
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Just a question that has been bugging me. When putting standard 850 cylinders on, there is very little clearance to the crankcases and sometimes a little trouble getting past the gasket. Is the sleeve OD the same as the OD of the standard skirts that go into the crankcases? Having never seen one it seems like they would be larger in diameter and not fit standard crankcases. When I read the posted document it said it was possible to make a 750 into a 920 - seems like that would be real tough!
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No its smaller but not by much hence the comment to remove too thin parts of the old skirt, but it also tells you to bore 10 thou off centre to the side for each bore so you could end up with the complete barrel too wide. Hence the comment to offer the barrel up to the crankcase mouth and remove material as required until the barrel slides in.
