Emergency Fuel Enrichment Switch 90hp

[bmdeangelis]

I have a 1998 90hp that has one of those red choke switches, on the middle carburetor, port side. It has 3 settings, "normal", "open", and "closed". From what I have read, in normal operation, when cold, it allows for additional fuel entry for starting, then as the unit heats up, a wax bead, expands, closing the unit, restricting the extra fuel flow.

I am having an issue in which my outboard will suddenly 'bog-out' after running WOT (I can run anywhere from 5 mins to 25 mins high speed, before it decides to bog-out......no rhyme or reason to it). I am trying to eliminate this choke switch as one of the problems, so I can continue to diagnose. When I put the switch to 'close', does that mean I am closing the fuel entry valve, and essentially acting like the unit does not even exist. Because when I have the unit on 'close', the engine starts just fine, and runs just fine, until it eventually 'bogs out', like I said. Again, it is my understanding that if I have the switch to 'closed' the fuel entry valve through the unit is closed, therefore acting like the unit does not exits. Is this correct??

Thanks for any and all help.

 

[robert graham]

Re: Emergency Fuel Enrichment Switch 90hp

same exact motor as mine. that switch is most probably not your problem, but you do likely have a fuel delivery issue. start at your fuel tank vent screw, pick-up line/check valve, fittings, primer bulb, fuel quick-disconnect at motor, fuel filter and fuel pump. when motor bogs, sqeeze primer bulb and if that helps, then you most likely need to repair/replace fuel pump. drain each carb onto clean white rag to see what's in them, then pump primer bulb to "flush" float chambers and needle valves. should be a fairly easy/inexpensive fix. good Luck!

 

[99yam40]

Re: Emergency Fuel Enrichment Switch 90hp

I have a 1998 90hp that has one of those red choke switches, on the middle carburetor, port side. It has 3 settings, "normal", "open", and "closed". From what I have read, in normal operation, when cold, it allows for additional fuel entry for starting, then as the unit heats up, a wax bead, expands, closing the unit, restricting the extra fuel flow.

I am having an issue in which my outboard will suddenly 'bog-out' after running WOT (I can run anywhere from 5 mins to 25 mins high speed, before it decides to bog-out......no rhyme or reason to it). I am trying to eliminate this choke switch as one of the problems, so I can continue to diagnose. When I put the switch to 'close', does that mean I am closing the fuel entry valve, and essentially acting like the unit does not even exist. Because when I have the unit on 'close', the engine starts just fine, and runs just fine, until it eventually 'bogs out', like I said. Again, it is my understanding that if I have the switch to 'closed' the fuel entry valve through the unit is closed, therefore acting like the unit does not exits. Is this correct??

Thanks for any and all help.

You are correct. With it set to closed it shuts off the passage so no fuel can flow through the prime start system

 

[bmdeangelis]

Re: Emergency Fuel Enrichment Switch 90hp

Thank you! Now I'll start diagnosing everything else.

 

[robert graham]

Re: Emergency Fuel Enrichment Switch 90hp

check for fuel vent/pressure issue, fuel pump may have bad diaphragm. is your primer bulb O.K.? the fuel system is very sensitive to either fuel leaks out or air leaks in. Good luck and let us know what you find!