I'm preparing to rebuild a CB550 engine, and have several used bottom ends from which to select the best components. Honda spec for crank bearing clearance is 0.0008" to 0.0018", with a maximum service limit of 0.0031". There are four different bearing "color codes" to choose from, depending on the crank journal diameter and bearing seat bore in the case. I have a bunch of used bearings in good condition, and if you assume all the bottom ends have their original bearings/cranks and you go by the "theortical" required bearing based on each of the coding combinations, there are bearings of each size variant....D-yellow (thinnest), then C-green, B-brown and A-black (thickest).
When I dry-fit the crank using plastigage and say, a D bearing and find the clearance on the high end of the tolerance, say 0.0025", can I substitute a good USED (and therefore likely to be slightly larger than when new) C, B, or A bearing as needed to bring the clearance down within (or closer to) the spec range? Do the bearings have enough split-line clearance to allow use of an A bearing in a crankcase bore that was originally fitted with a D bearing?
My budget precludes ordering all new bearings from DSS or Honda (just thought I'd toss that out there to head off the easy answers). Gurus please step up and provide feedback from the "been there, done that" perspective.
Thanks in advance,
Kevin in warm, sunny Texas