Cr 500 -was the cylinder sleeved?

scooter_74

Member
Nov 26, 2005
2
0
Hi,
New to the site. I have a used 1991 Cr500 (Honda). I was checking things out; noticed carb was dirty, pulled it, saw the middle upper reed had carbon color to it. Pulled the reed bloc and noticed a hair-line fracture up the piston. Pulled cylinder and see some "porting type grinding" around the exhaust port as well as the intake ports, and really only in these areas. The lower part to the sleeve has some grinding on weld/ fill. Would it be safe to assume this is NOT the original factory work and the thing has a sleeve inserted?
I priced a cylinder through the Service Honda web site and am quoted a price of $284 for a new 1998-2001cylinder. Is this Cylinder compatible with my 1991?
Any help is gratefully appreciated.
-Derek
 

Tony Eeds

Godspeed Tony.
N. Texas SP
Jun 9, 2002
9,535
0
Welcome to the site! Be sure and go to your User CP and update information relating to your location, type of riding, etc.

I am going to move this to the CR / KX / RM / YZ (2-Stroke) Discussion forum. I will get AJ to get you an answer. As the godfather of the current CR500 he likely know more than anyone else on the planet about the bike.

I was going to suggest that you contact Service Honda, but it appears that you have already found them..

As one of the best resources on the planet, I highly recommend MX & Off-Road Performance Handbook -3rd Edition - by Eric Gorr. It can be purchased via this link. I have a copy and have found the book to be very thorough in its’ discussion of the various components of a motorcycle. Eric’s many years of experience are self evident. Additionally, Eric Gorr’s Forward Motion Racing is a valuable resource for engine work. Both the book and Forward Motion are links in the bar on the left side of the site.

After that grab a spot on the couch and start a new thread in the New Member? Welcome! Go here first forum and tell us a bit about yourself. How long you have been riding, what kind of riding you prefer, where you are located, etc. We will do our best to hook you up with fellow DRNers in your area.

Again, welcome to the site, and shout if you have any questions!
 

AJ Waggoner

Crash Test Dummy
Nov 5, 1999
4,368
34
like Rcannon mentioned ,
the CR500 cylinders have a steel sleeve from the factory.

yours sounds oem (stock honda) ,
with some porting work done.

any welding inside the sleeve area sounds strange! but maybe i misunderstood you.

is the bore /piston size standard ,, or half a mil over bored, 1 mil over, 2 mils ?


1991 thri 2001 CR500 cylinders all carry the same OEM Honda part number

12100-ML3-680 -

and are interchangeble on those various year model cases with the coprrect size piston/rings for the cylinder used. (for example, if its stock or over bored)
 

scooter_74

Member
Nov 26, 2005
2
0
Thanks

Thanks for the info. I have tried to contact Eric Gorr, and will continue to try. His shop seems to be the most popular among discussions. The 'grinding' I was referring to does not appear to be much of a professional porting job (not that I would know, but I would expect more work). The grinding is just along the sleeve skirt and the cylinder housing, not deep into the intake/ exhaust ports. Again I could be wrong, for I have never had a bike worked on in this manner.
Thanks for the advice, and it is definitely a steel sleeve within the cylinder, just looks a little crude (I used to work in a machine shop and have a bit of experience with milling).
Thanks,
Derek
 

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