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tri5ron's avatar
tri5ron
Explorer
Jun 09, 2017

onan microlite 4000 wont start

hello all,

I'm back with ANOTHER genny that has problems, and can use some help.
1997 24' Class C Winnie Itasca,
Onan Microlite 4000 with 220 hours
-fuel tank full
-Battery good
-Oil level good
-Fuel pressure to genny good, (checked by pulling fuel line from genny carb, cranking over genny, and gas pumped very well from fuel line)
-Spark seems good but could be slightly weak (?) Blue color spark

Genny will crank over fine, (and will even start for a second) with a shot of Starting Fluid,... but will immediately die.
I can keep it running with quick repetitive shots of starting fluid, but it will die within 1 - 2 seconds of the last squirt of fluid.

any suggestions or what to check next ?

6 Replies

  • Yep, something is plugged up inside the carburetor. Float bowl needle and seat, main jet, fuel galleries, etc. Clearly fuel is getting to the float bowl, but, is there fuel IN the float bowl?

    Chum lee
  • Laugh a minute...35 years ago. Constipated Onan carburetor.

    Disassembled it and boiled it in oxalic acid for a half hour. Neutralized in diluted caustic soda..it worked. Ever see a grape tinted Onan carburetor? Every shop within 100 miles tried to rebuild it. Few shops had 165 PSI air pressure and a rubber tipped blow gun :)
  • try soaking the carb with 'seafoam'
    buy it at the auto parts store