Scored Piston

[Rufffy]

Hi, I have a 99 GSXRFI with only 50hrs, I toke it in for the 50hr service and the dealer informed me that the rear piston has light scoring and whants to strip the motor down to investigate. I have never roled the craft, very carefull with flushing and then fogging after every ride. Will the motor continue to run with the scoring or is it just a matter of time. Compression is the same in both cylinders and the craft still runs hard. Feed back please.

[Bill O'Neal]

It depends upon how bad the scoring is. I have no idea what your dealer thinks is "bad".
Is it very light vertical lines on the piston, as viewed through the rave slots? Or, did he remove the head and find scoring on the clyinder walls?

[Rufffy]

Bill, the dealer removed the powervalves and looked down the small slot, I also looked and I would say they are very fine marks. Nothing deep and you had to look very harf to notice them.
Would SBT ship a motor to Aust with out warranty or exchange? if I need.

Thanks

[Dick]

You need to pull the head like Bill mentioned. See if the scores are in the cyl walls. If the compression is good it's probably not from seizure. If one cyl is way different than the other you may want to look over your oil lines, check valves etc to make sure your getting good oil to both. Usually you will get a gray pasty look to things from low oil flow. It's the worn aluminum mixed with oil, fuel etc.

[Bill O'Neal]

Very minor scoring is pretty common and normal when viewing a piston through the rave slots. Look closely at the rings to see if they are free and no major scoring on the faces of the rings. If not, you probably have a good to go motor. If it really bothers you, pull the head to look for clyinder wall scoring.

[Rufffy]

Bill,

Thanks