Chainsaw Repair

Parts Catalog for the Echo cs-5500;
http://www.echo-usa.com/documentation.aspx?s=cs-5500&c=en-us
Intake adapter part number 13051032430;
http://www.ereplacementparts.com/adaptorintake-p-529155.html

You should be able to get the intake adapter at one of the local dealers.  Probably should go through the fuel system too.  New lines and a new filter.  New carb diaphragms and a new air filter. 

I switched my 5500 over to 3/8 chain (new rim) with an 18 inch bar and it does quite well.  Add another outlet to the side plate on the muffler and ditch the screen!