RS250 cylinder heads

**Tue Sep 12, 2006 11:55 am » Post: #1 » Download Post**

Found some 1989 RS250 cylinder heads that look very similar to MC21 anyone ever tried fitting these?
_________________
MC21 SP

**Tue Sep 12, 2006 12:34 pm » Post: #2 » Download Post**

They are nothing like, and wont fit. The PCD of the studs is different and a differnt size. The RS head is also designed to work with the O ringed barrels of an RS motor and not the head gasket on the 21. The MC21 head is very good so there isnt much point be designing a 21 barrel to try and fit them.
_________________
If I have to take the carbs off once more...

**Tue Sep 12, 2006 12:34 pm » Post: #3 » Download Post**

If they look that similar to MC21 heads, then they will be MC21 (or MC28) heads.

The RS heads are totally different.
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

Check us out on Facebook! Please "like" our page!

**Mon Sep 18, 2006 3:06 pm » Post: #4 » Download Post**

Here's the link they also had some barrells but look like they've gone doesn't look like o ring to me

http://cgi.ebay.co.uk/HONDA-RS250-RS-250-RACING-MOTORCYCLE-CYLINDER-HEADS_W0QQitemZ250009772781QQihZ015QQcategoryZ10460QQssPageNameZWD1VQQrdZ1QQcmdZViewItem

Would barrels have fit?
_________________
MC21 SP

**Mon Sep 18, 2006 3:37 pm » Post: #5 » Download Post**

Yes those are RS250 heads, and they work with O rings, The o-rings are recessed into the cylinders, so no the heads still wont work with mc21 barrels.
_________________
If I have to take the carbs off once more...

**Wed Sep 20, 2006 11:37 am » Post: #6 » Download Post**

What I meant by would the barrells have fit I ment the RS250 barrells if I could get my hands on those?
_________________
MC21 SP