Slip the slide guide o-ring over the boss on the underside of the slide guide and make sure it is more or less seated in the o-ring groove. In order to prevent the o-ring from becoming dislocated, all operations from here until the main jet has been tightened must be performed with the slide guide upside down. Slip the emulsion tube through the slide guide. It is normal for the fit to not be as tight as it was between the used components (this will tighten after the main jet is screwed in and the components have been though enough heat cycles). Orient the emulsion tube’s keyway so that it will align with the locating pin in the carburetor body’s corresponding bore. Slip the slide guide/emulsion tube assembly into the carburetor body until stopped by the tabs at the top of the slide guide. Push the guide home as far as you can – it’s OK if you can’t get it all the way in yet (Do not file the tabs in an effort to ease assembly! Doing so will ruin the slide guide). If the emulsion tube became dislocated during any of the previous steps, confirm key slot & locating pin alignment and push it back in position. Install the main jet and tighten to 16 in-lb (1.8 Nm), which will fully seat the slide guide.