Thread: Piston size
02-10-2007, 11:20 PM #1
I know it has been posted before, but I can't find it. Where on the cylinder is the size stamping? I want to replace my pistons before one goes. My engine just turned 100hrs today and I want to be safer than sorry. Rather do it now than during the summer.
Last edited by CanadianGPR; 02-10-2007 at 11:24 PM.
02-10-2007, 11:58 PM #2
Is compression ok ? On a stock ski 100 hours is not that much
02-11-2007, 02:14 AM #3
The compression is fine, I'm running a 160lbs head and would rather replace cheap pistons now than take out a cylinder and have to repair it, it's not that cheap up here on the west coast of Canada. And I would rather do it now when I ride only once a week, then do it during the summer when I ride 3-4 times a week. I know 100hrs isn't too much but I ride hard and full out most of the time and lots of tugboat wake jumping. My stock gp800 took out a cylinder at 90hrs.
02-11-2007, 09:55 AM #4
Rich instead of just buying new pistons you might consider doing what I did to my stock ski.
Sell off your 1200 cylinders and pistons - you can sell a matching cylinder/piston set for $200 to $300 each. Your high compression head is worth another $200.
Then install a BB top end. Anything from a 1300 to a 1390 (or larger). On my ski I put on stock 1300 cylinders with a Riva head. You wouldn't believe the difference.
I have a couple extra top ends (including a new 87 mm set-up sitting on the shelf at Lowell's) that I would sell if this idea is of any interest. email@example.com
02-11-2007, 10:12 AM #5
the cylider size is the number that is stamped on the cylinder - look for a number from 0 to 20 - top of cylinder on the exhaust port side
02-11-2007, 11:41 AM #6
02-11-2007, 01:15 PM #7
If you dont go phillips route I would suggest buying all three pistons the largest available(I think c is the largest)and have your cyls. diamond honed to fit.Then your the same on all three with a like new fit.Hope this helps.
02-11-2007, 03:08 PM #8
OK, I am curious
How thick is the nicasil?
How can you tell if a used cylinder has enough plating left or if it is worn down too thin?
I would think there is a limit on how much you can hone off?
Is it possible to measure this this or tell by looking at a cylinder?
02-11-2007, 04:07 PM #9
Im not 100% but im pretty sure the Nic doesnt wear hardly at all.Its much stronger than the rings as the rings wear before anything.Maybe after 250-300 hours the Nic might start to thin a little.
02-11-2007, 06:02 PM #10
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