hi, is it possible to change the valve guide oil seals on a crossflow without taking the head off/ thanks.m.

Yes

Rocker cover and valve gear off, plugs out.

Cord down plug hole then turn engine over so the piston jams this up under the valves, you can now remove the collets in situ as the valve cannot fall, change seal and re- assemble, pull out string and move on to the next one.

Regards Mark

[Edited on 6/4/09 by mark chandler]

I have the proper tool if you want to borrow it, will need compressed air 100psi plus.
dave

Compressed air adaptot tool is cheap, collet remover replacer tool is more expensive --- Agriemach sell both

Agriemach item numbers PM-D2110 & PM2211

http://www.agriemach.com/product_info.php?products_id=844

http://www.agriemach.com/product_info.php?products_id=813