Spun Cylinder Sleeve

[Queef Chief]

Finally getting around to my '85 CR500 conversion, and opened up the motor last night. When I bought this bike, it had low compression, so I never heard it run.
Now to the topic:
The sleeve appears to have spun nearly 1/4" inside the cylinder(I'm guessing). The bore is stock at 89mm, so I'm thinking whoever bored the cylinder out for the new sleeve had their clearances wrong, and as the cylinder got hot, the sleeve torqued a little. Have you guys seen this before? Im hoping the cylinder can be bored for an oversized sleeve, and everything will be fine.


Sent from my iPhone using Tapatalk

[John Tice]

A 500cc cylinder liner needs a .004” press fit. The installer probably didn’t use or didn’t know how to use a dial bore gauge. The installer also probably needs to upgrade their honing equipment. 2 stroke cylinders are difficult to properly hone. At www.smallenginemachineworks.com & www.northwestsleeve.com we use only Sunnen brand honing heads. If you access our site an example of the equipment can be viewed & is explained. www.smallenginemachineworks.com


John Tice
503-593-2908 Alternate 541-508-3944
www.smallenginemachineworks.com & www.nwsleeve.com
Turning Custom Cylinder Sleeves Since 1971
http://forums.everything2stroke.com/...d-the-Shop.com

[Queef Chief]

Thanks John, I was hoping you or some of the other engine builder gurus would chime in. Is this something you can fix for me, and if so, do you do port work as well?

[John Tice]

We are buried up to our hips with custom sleeve installations & leave the custom port work to others. Your cylinder needs a proper sleeve installed with the correct shrink fit. Give me a call 503-593-2908