swmichsx
New member
200 miles ago i rebuilt my top end. everything was checked and well within spec. yesterday my sled broke a ring and trashed a cylinder. i used brand new pistons , rings and gaskets. they ere the SPI ones. my sled is a 97 SX 700 and the bad cylinder is the mag side. just wondering what might have caused this?
Last edited:
9801srx
Member
did you check the ring end gap before assembling? some times rings need to be filed to get enuf end gap,with out enuf the ends butt together when they get hot and break.
swmichsx
New member
yes i did. i filed them myself and constantly squared them in the bore to check. the other 2 cylinders are fine.the were installed correctly as well.
redrider24940
New member
know your pain Bud. Seen ya on my thread. I will keep ya posted on if I find anything
swmichsx
New member
thanks
The ongoing rule of thumb here is to use OEM parts if you want reliability. I know that doesn't help you in your current pickle, and it doesn't explain what actually happened, but it may help alleviate future pain.
swmichsx
New member
i know. i will be using yamaha rings on all three cylinders when i put it back together. i have heard that the SPI pistons are good but the rings suck!!! i believe!!!!!!!!!!!!!!
snowfoxsx
New member
same thing happened to mine with spi kit
swmichsx
New member
when you put it back together what parts did you use?snowfoxsx said:
YamahaSXR700
Member
my brother put some SPI piston on hiis tcat1000
mopar1rules
Active member
you say you broke a ring.....did the ring stop pin back out, causing the ring to spin and catch/snag the exhaust port, causing the beakage?
swmichsx
New member
i will look right now!!!!!!!!!! nope, the pin looks just like the the ones in the other 2 cylinders. the gouge marks are actually on the intake side.