Pistons

My to my displeasure I was forced to remove the cylinder head from my 1977 KZ-1000A1 due to an oil leak. After removing the head I discovered one of the exhaust stud bosses was cracked, but not broken through completely yet, so in hindsight it was good that I removed the head or I would never have been able to see the cracked boss. I have sent the head off to APE to do whatever work is necessary to it, including repairing the exhaust stud boss crack. Hopefully I won't receive any really bad news from APE and the head and valves will be properly reconditioned. Tonight I gave the cylinder bores a close look and the cylinder walls aren't the best and I have decided to pull the cylinders and have them examined by APE also. I can't be sure, but it looks like the pistons sat in one place for a long period of time and there is some minor pitting in the cylinder walls. If the worst case scenario should arise and I am told I need to bore the cylinders oversize is there a consensus on who makes the best pistons for a close to stock configuration? Thanks for any advise on this.....

Rick H.

MTC or Wiseco are the top choice for pistons.
You can get stock compression , lower or higher and the kits come with head and base gaskets etc and the pistons are forged not cast so are higher quality than the stock cast items.
You would need a 71mm 1045cc kit if your current bore is stock.
The stock motor will benefit from a compression hike without any other mods if required .
10.25 -1 is the popular choice.
Wiseco come with circlips and MTC with teflon buttons so the Wiseco's would be the first on the list if circlips are your preference.
Whatever compression you chose the cost of the kits are pretty much all the same.

Thank you for the reply zed1015. Are there any negatives I should be aware of in going to 10.25 compression versus the stock compression? My initial goal was to keep this bike as close to stock as possible, but if bumping compression up causes no other issues it sounds like a no brainer.

Rick H.