1990 Johnson Evinrude "ES" Cross V 88 thru 115, 150 thru 175, P/N 507874, Page 81Get this manual
Carburetor Body
1Check all drillings and passages with syringe filled with isopropyl alcohol
2Visually inspect all gasket surfaces for nicks or irregularities
3Check for excessive throttle shaft playCheck for throttle valve
misalignment
If necessary, remove the calibration pocket core plugs to inspect the pocket for damage or restrictions Drive small punch not more than Va in (3 mm) through plug and pry out