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1978 CR250 cylinder-Sleeve vs Rechrome
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Author:  SFx73 [ Fri Aug 08, 2008 6:57 pm ]
Post subject:  1978 CR250 cylinder-Sleeve vs Rechrome
I have a '78 CR250 that hung a ring and damaged the cylinder. Does anyone have any experience with a sleeved cylinder compared to a rechromed cylinder? I will only race this bike about 4 times a year and practice with it a little more. Also, if I rechrome it, what would be an average price? Thank you.
Author:  FTE [ Mon Aug 11, 2008 12:54 pm ]
Post subject:  Re: 1978 CR250 cylinder-Sleeve vs Rechrome
Personally, I go for Nikasil replating (I don't think you'll find a place to rechrome) over sleeving. The upside to sleeving is that you can do overbores down the road when you need to have a fresh top end. The downsides are that the sleeves rarely perfectly match for the ports (though you could probably smooth that out with a proper epoxy) and that the cylinder is no longer as thermally efficient.

I think the up front cost is roughly the same if you factor the cost of the sleeve in. Replating is about $200, with a bit more if the cylinder needs a deep gouge repaired.

The replating services I see mentioned the most with good reports are:

http://www.usnicom.com/ (I believe Eric Gorr uses them)

http://www.powersealusa.com/

http://www.mt-llc.com/
Author:  Moto_Recon [ Wed Aug 13, 2008 12:29 pm ]
Post subject:  Re: 1978 CR250 cylinder-Sleeve vs Rechrome
Hello,
The damaged chrome can be stripped. If there's damage to the aluminum bore, it can be rebored to the next cleanup size and then replated , Nikasil, whatever. This way you don't need to worry about port alignment, or a poorly fitting sleeve. If you bore and replate, you have just given yourself a new, your standard, bore size.
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