50hp backires at idle

[scotttt61]

Hi !
Just bought a 2005 50hp johnson j50plsoc....took it out, ran good,planed out....then started to loose power like starving for gas.Will not achieve full power.
Had fresh fuel but boat may have sat...fuel didn't smell though
Checked plugs...look good
checked compression , even 140
even tried aux. fuel bottle up by squezze bulb/motor to see if it was supply line or fuel tank but runs the same
ildes even up alittle but then backfires rpm drops alittle and then comes back up .
Put some techron in the fuel to maybe clean out carb?
thank you

[Joe Reeves]

It does sound like the carburetors need cleaning and rebuilding (dismantle and clean). Clean the high speed jets carefully, manually with a piece of single strand steel wire as solvent just doesn't do that job properly. HS jets are located horizontally in the bottom center portion of the float chamber, way in back of the float chamber drain screw plug.

[scotttt61]

Thank you !