Out of round - big problem ?

[A100man]

Hi All

I'm currently fiddling about with an XJ/FJ 600 engine I intend to transplant into an 80s XJ550 - but due to the PO having left it outside it has suffered a corrosion seizure on one of the bores and so I have sourced some 'new' ones.

The new ones aren't 100% either and so I got a mate to measure them for wear. Standard bore is 58.5 mm and we measured 58.55 x 58.56 (tranverse vs longdit.) on most bores meaning that they 'might' be up to 0.01 mm out of round. I say might since I'm sure there must be a bit of measurement error here. BTW wear limit is I believe 58.6mm

Should I be concerned ?

Rebore is not really an option due to shortage of o/s pistons - even standard rings are about 40 quid per pot so for 4 lots more than teh whole bike cost as a bag o' bits.. !!

Best

JS

[bladerunner]

Depends a lot on how you measured them..and what with! Try measuring the top and the bottom of the bore and see how they compare....that should at least give an indication of wear.
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Current bikes...cbr929, KDX200's, Rd125lc mk2, RGV250's

[A100man]

Thanks - they were measured using a spring loaded telescopic probe thingy and a micrometer for front/back and side/side and a 'three legged internal micrometer'
for bore. In fact my first post was wrong . The 58.55 and 58,56 measures was top bottom difference the front/back and side/side (out of round) was about 1 thou as the linear micrometer was imperial..

Cheers

J

[bladerunner]

Telescopic gauges tend to be a bit hit and miss but 3 sided bore gauge works. 0.025mm sounds pretty damn serviceable to me!
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Current bikes...cbr929, KDX200's, Rd125lc mk2, RGV250's

[A100man]

[hmmmnz]

yeh bolt the fucker up. big deal, you burn some oil and your down on power, whoopdie shit,
its not a race bike that you are trying to get as much power as possible,
it'll run fine, chuck some heavy oil in it and she'll be good
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the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[A100man]