NooB with 93 RM250 sleeve groove question

[loach1]

I just picked up a 93 RM250 in a few pieces. Nothing too terrible, but it has a new cylinder sleeve installed and needs a few minor pieces to stick it together. I think I have a problem with the new sleeve though.......


The original cylinder head is sealed by 2 o-rings, but the new sleeve does not have an o-ring groove. The sleeve also stands about 0.1mm proud of the 'deck'. I have searched the web to see if this is normal, maybe an improved way of doing things, etc, but came up with nothing. I suppose using a copper gasket I could obtain a pretty good seal without the small o-ring, but if it isn't normal practice then I don't want to mess about - I'll get the groove cut.


Thanks for reading and if you know the answer - groove needed or not?, please reply!

David in NC

 

[Pete Payne]

There should be an inner and outer oring groove . Maybe someone installed the wrong sleeve from an older bike ??? How do the ports line up ???

Sounds like it needs to be put up in the lathe on an expanding mandrell and be faced off and have the oring groove machined into it .

 

[whenfoxforks-ruled]

I would think it a normal process to square up/face the top of the cylinder. Skipped a couple processes, saved more money? Or, our outstanding depth of the working class, that should be working at mcdonalds?

 

[loach1]

As I suspected then - it needs to go back to the machine shop. Luckily I got a receipt for the work with the bike so I know where to take it to complain. The ports line up well and have been matched quite tidily. Looks like an oversight on the facing and grooving.

Thanks for your responses!

 

[Pete Payne]

Also if the right sleeve was used you normaly do not have to remachine the inner oring groove .

 

[upstateny]

I also have a 93 RM250. It has an Iron Sleeve in it. It did NOT require having the Inner O-Ring groove to be remachined.

 

[whenfoxforks-ruled]

Sleevers, pffft! I want my 77-rm370 bore coated! Where do you get the copper/felt gasket to replace the o ring set up from? The sleever?