[VA51L]

Hey guys I'm staring to replace my crankcase, due to some damage from a crash to the engine block. Can I reuse the same piston rings or would I need to replace them? The bike only has 9k miles and I don't want to replace them if its not necessary.

Bike details:
2017 GSXR 1000 9k miles

 

[2014wiringswitch]

I would say reuse them, also check the service manual for Piston ring free end gap and Piston ring-to-groove clearance
That should give you the tolerance (standard and limit) and % indication of how much they are worn.
You need a good tool to measure this (feeler gauge / Thickness gauge)

If run upside down, might replace
if run without oil might replace
if run as circuit winning racer might replace (?, what do racers say?)

Pictures and walktrough might help others if you can, would be nice to see this job.

 

[VA51L]

I would say reuse them, also check the service manual for Piston ring free end gap and Piston ring-to-groove clearance
That should give you the tolerance (standard and limit) and % indication of how much they are worn.
You need a good tool to measure this (feeler gauge / Thickness gauge)

Thank you!!! Would I need to break in the new block for the first 500 miles?

 

[2014wiringswitch]

No if old parts that are worn-in are reused, just the initial extra oil/grease mix as mentioned in other thread to help first start, but a few turns with starter without plugs or spark should build enough oil pressure.

End gap is mostly common on dirt bikes, every 30 hours replace/check, insane:

Also check how manual states to insert the gaps opposite of each when installing.

for <2014

1st ring (4) and 2nd ring (3) differ in shape.

Face the side with the stamped mark upward
when assembling.

Install the piston rings in the order of the oil ring,
second ring and top ring.
a) The first member to go into the oil ring groove is
the spacer (1).
After placing the spacer, fit the two side rails (2).

When installing the spacer, be careful not to
allow its two ends to overlap in the groove.

c d e = gap position in circle:
.............d........
..IN c EX e..

“C”: 1st ring and upper side rail
“D”: Spacer
“E”: 2nd ring and lower side rail

 

[Beairsto Racing]

I can't think of a good reason to re-use old piston rings, other than false economy.
They're relatively inexpensive, consider the damage if they fail.

Only 9 thousand miles...give that some more thought, consider the harsh environment that they operate in, the # of heat cycles that they've endured etc.

It's not a lawn mower, it's a high rpm, precision machine.

Once the rings are compressed, installed, subjected to heat cycles and wear...they are not intended to be re-used again, if they are removed from the bores and allowed to expand again.
Is it worth the risk?

 

[2017Dave]

Change em.

 

[craigfer63]

Change em ? This is a difficult question, which parts to renew ? Main bearings, big end bearings, piston pins, gaskets, seals, valve seals ? What would be a bike shop mechanic's agenda ? Minimum cost to shop ?
Personally, as an exercise, I would have to Plastigauge the bearings and record findings.
Being an eternal tight arse (descended from Scotsman) If it ain't broke don't fix it !
Rings are an easy one but wont make any change to performance, at 9k miles.