Chainsaw Repair

Update:
I finally got it apart and re-assembled. My bushing was steel not brass. Must have been an earlier version. I filed the crimp off (I don't think it would have helped having it anyway). Used my propane torch to heat up the outside a little, while also using the short leg of a allen wrench that fit in the hole to pry up. Popped up easy then.
Cleaned it all up w/brake cleaner. Inserted the new duck bill and put a little RED Loctite on both mating parts and tapped the bushing tight with a drift pin. 
The only messy part was putting the screen back on with JB weld. When/if I do another one, I'll put the JB Weld around the perimeter of the valve body, and push the screen into it.

I hope this helps anyone else wanting to re-build the check valve. After you've done one, you see what works and what don't, it's really easy. I got the duckbills from my Husky dealer for $1.49 each.

Thanks for the report.  Good job.

Just an update to my previous post.
I've done several of these now, and have found that a just a very small touch of Aviation Permatex to the duckbill side shoulder when installing it will guarantee a airtight fit. I like to tap the bushing snug but not so tight that I may mess up the small shoulder. After rebuilding one I still didn't have the proper sealing when testing it. I took it apart and added the Permatex, reassembled it and problem solved. I did let it cure over nite before installing it.

I think the screen is more safety net to contain the check valve part/parts if they fail, from having direct access to the crankcase then being a filter.

Fantastic, that is ingenious. 

Here is a rebuild of one i did. I just used a sander to sand down the filter.