03 25HP 4 stroke Yamaha

[Tudawgz]

Need sum help. Moter run great last year. One pull crank. Did not winter treat. Im in central texas. Cleaned plugs, fuel tank, fresh fuel, replaced fuel bulb, fuel lines are good, gets fuel, gets fire. Moter will crank and idel for a short time but then dies. I kept messing with it and found that if I restrict the air intake by placing my hand or it and leave a small gap for the air to enter the carb it runs great. I give it more fuel and allow more air into the air intake tube it runs great. When I remove my hand from the intake tube it dies. Its like it is getting to much air mix...??? I have been reading all over the forums and found some things that are close but not quite what I have issues with. Any help would be great. Thank You

 

[BaileysBoat]

Re: 03 25HP 4 stroke Yamaha

Sounds lean for sure. Something settled out of the fuel over the winter?

Will it run of idle at higher speed?

Might find some help here; http://www.boats.net/parts/search/Yamaha/Outboard/2003/F25MSHB/CARBURETOR/parts.html#

 

[cousinabe]

Re: 03 25HP 4 stroke Yamaha

check your carbs.
restricting the air intake indicates a blockage in the pilot fuel circuit.

physically remove the main jet,pilot fuel jet and the emulsion tube and carefully clean them.
also make sure the transfer passage between the main well and the pilot fuel orifice is clear.
dont forget the rubber pilot fuel jet plugs.

 

[Tudawgz]

Re: 03 25HP 4 stroke Yamaha

Thank You for the replys. I will check it all out. I am not well versed with small carbs but if I take it apart I can put it back together... most of the time I will also post my findings.