Rebuilding 1990 rm250 engine

[eddie1]

I just bought a new sleeve and piston kit for my bike.

Can you guys give the steps to doing this correctly so i don't messup.

 

[sixds]

buy a service manual

 

[slickpuss]

A sleeve? A manuals not going to show you how to press in a new sleeve. I doubt less than 0.5% of the people on here have ever pressed in a new sleeve.

Are you sure it isnt a ring and piston kit?

 

[N3WFI3]

bring it to a machine shop if you want to get a sleeve put in

 

[Ol'89r]

I just bought a new sleeve and piston kit for my bike.
Can you guys give the steps to doing this correctly so i don't messup.

Sure, no problem. :nod:

Take your micrometers and measure the OD of the sleeve.

Then, using your boring bar, bore the cylinder out to within .0015" or .002" undersize or whatever the sleeve manufacturer recommends.

Using your inside micrometer or bore gage, mic the cylinder to insure you have the proper bore.

You can also use your vertical mill with a boring head if you don't have a boring bar in your garage.

If the sleeve has a register or step at the top, you will also have to bore the cylinder to accept that.

After boring the cylinder, heat the cylinder with your torch set to about 300 degrees and freeze the sleeve.

Then, using your 20 ton shop press, press the sleeve into the cylinder being very careful to properly line up the ports. Most of the time, if properly heated, the sleeve will drop most of the way into the cylinder, but if it stops half way down, you will need to use your 20 ton press to seat it the rest of the way.

Then, take your porting tools and die grinder and match the ports in the sleeve to the ports in the cylinder.

Put the cylinder back in your boring bar and bore it to fit the piston.

After boring the cylinder, take your porting tools again and do a final blend on the ports and at the bottom of the sleeve and chamfer the edges of the ports. Also chamfer the bottom of the sleeve.

Chuck the cylinder in your vertical mill and re-surface the head gasket surface.

Finally, take your Sunnen hone and hone the cylinder to size leaving a crosshatch pattern when you are done.

See, it's easy, :debil: all you need is about $30,000 worth of equipment in your garage or access to it.

Or, you could take it to a machinest. ;)

Good luck. :cool:

 

[Rotorranch]

Or you could forget the sleeve, and do the right thing. Send the cylinder to a replating service, like US Chrome, and have it replated. You'll be way better off than putting a sleeve in the cylinder.

Rotor