BannedCR500Riders.com

Not a bad top end setup you say? Ported cylinder, new Wiseco piston, fresh hone job. There's only one problem, can you see it?


www.ebay.com/itm/280865368619

Everything you see is included. The power valve assembly is complete and is included

most likely hes never heard the term "relieved bridge"

Well, that too but something even more important. It's about the only piece of info you get on the parts from the pictures.

Apart from the head looking a bit ropey, especially around the plug hole, and shrapnel damaged on the squish band, it looks like a pretty good deal (by Aussie price standards, anyway) Piston at 91.00, and barrel reading 91.3mm on the verniers seems ok ? You can always relieve the bridge yourself. . . . Worrying thing is he claims the power valve is complete, working and included in the sale. . . . . . Where do I get me one of them 5hunny models with the power valve ? Like that dude who tried to Ebay his 6 speed CR500 gearbox . . . wonder if that came from the mythical PV version too ?

His caliper reading of 3.5905" was my concern. Either his gauge isn't getting a good reading or someone honed that cylinder way too far over because 3.590" would be like .010" larger than the piston which is way too much clearance. It should be more like 3.585" giving it .005" clearance. 91mm being the last bore size for that cylinder and it already being too big I would say it's re-sleeve time. The only way I'd use it is if I had the piston coated with a heavy layer of Swaintech PC-9 which would take up about .004" of that slop. Dial calipers are pretty accurate (easily within .001") but it all depends on the person using it.

You might be right about the clearances. I have never put much faith in clearance measurements really, especially measured like that . . . . proper way is with a T dial or T gauge, and all the way down and around the bore. All I ever really concern myself with on big engines (200cc and down are fussier about piston slap, especially those ones with the short piston skirts) is ring end gap. I push new rings in the bore and check the end gap at about 10 or 15 mm increments down the bore. If the end gap measures within tolerance at each location, we're golden. Run the sucker, I bet you can't hear piston slap on a 500 ! At 91mm, you're done when it wears out though, so you wouldn't want to pay too much for it !

and the cc cast markings being ground off

gregrobo wrote:and the cc cast markings being ground off

True dat ! didn't notice it till you mentioned it . . . . .

No shizzz, I didn't see that either. There's no tellin where that port job came form either which would bother me. No port work is always better than bad port work. It doesn't look like a hack job but....