Hi kevbar,

In case you don't have it, here is the Operator's Manual for your saw:
http://m.husqvarna.com/ddoc/HUSO/HUSO1998_USen/HUSO1998_USen__1018843-26.pdf

Here is the illustrated parts list:
http://www.ereplacementparts.com/husqvarna-254-198604-chainsaw-parts-c-114486_114487_114811.html

Please refer to page H of the parts list for details of the oil pump.

Here is the complete workshop manual for that series of saws:
http://www.scribd.com/doc/41555952/Husqvarna-Service-Manual

The manual includes this illustration for some saw models - I do not know if this includes the 254:

[Linked Image]

Here is the key illustration for removing and dismantling the pump, from page 71 of the workshop manual:

[Linked Image]

I've circled the retaining screw in red. If you remove that, the pump can be lifted out. However, note that in the illustration, the worm gear that drives the pump appears to be absent, having already been removed. At this point I do not know if you just lift the worm gear with a couple of screwdrivers to remove it, or whether the 254 is one of the models that have the worm gear pressed onto the shaft, so it has to be removed with the puller shown above, before you can remove the body of the pump.

Note this specific instruction for reassembling the pump:

[Linked Image]

As far as I can tell from the instructions, the puller is a very special tool to screw onto the worm gear. I am mystified by how that could be done without previously removing the plastic plunger that the worm gear meshes with, however.

Please report back, if possible with pictures showing the process, so this thread can be useful in our archives.

Last edited by grumpy; 06/12/12 04:41 AM. Reason: Add detail