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750 K2 Strip & Rebuild - help please

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K2-K6:
The collective noun used by oil manufacturers is "lubricity" in description of how slippery an oil or fuel is. Covering a multitude of properties including shear stability, absolute shear strength etc.

It's very hard to form a competent position that can clearly attribute better lubricity to synthetic oil over and above a mineral oil. In other words they don't really differ much, if at all. It's the assumption that synthetic is more slippery that undermines most arguments against using synthetic.

The properties it has that are capable of outperforming mineral are in flow characteristics/viscosity range (high VI range) oxidation stabilisation,  raised heat tolerances,  all of which are a valuable asset in this situation. 

Bryanj:
I think one of the problems is people see synthetic but think friction modifiers which early synthetic car oils had as well and its those that cause clutch slip

Oddjob:
Getting those ball bearings out isn't for the faint hearted I'd imagine. Much better to have a spray that can dissolve the sludge without having to resort to drilling it out. Maybe someone like Ash can get some of the typical muck left in this passage and see if he can find a fluid which readily dissolves it, brake cleaner seems to work for instance but doesn't by all accounts do it totally. Knowing Ash he'll invent some exotic cocktail that will solve the problem without having to remove the ball bearing and potentially ruin a good crank.

Lobo:
Surely the problem Ken, is that you’re unable to directly point any spray at the column of sludge given the geography of the holes. So (useful) mechanical degreasing / washing out is off the cards. Next issue is the 6(?) mm column, 1” high (?) of compacted ‘plastercine’ - how are you ever going to know it’s all dissolved?
Could ultrasonics be used? - though I guess the mass of the crankshaft would negate that?
The (grinding) method of removing the balls Ash put out on his link would be easy enough for most DIYers - given they had enough nous to get the CS out in the first place?

Oddjob:
Odd thing is that the 500/550 crank only seems to have 2 ball bearings at each end, so how were the inner rods lubricated?

Didn’t someone post they’d sprayed brake cleaner down the holes from the conrod pin?

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