Help with 2002 mercury bigfoot 9.9 fuel pump?

[kevinelt]

I have this 2002 mercury 9.9 bigfoot 4-stroke. It idles great. Both cylinders a firing. but when advancing throttle in gear the motor cuts out. If I add some choke it runs. Does the fuel pump on this motor have a replaceable diaphragm? If so could this be the problem?
Any ideas would be helpful.

 

[Star]

Re: Help with 2002 mercury bigfoot 9.9 fuel pump?

How long since it was running? Did you treat the gas with anything? It could be a pluged up high speed jet.
If you choke it and open a bit can you get past 2000 rpm. It could be the accelerator pump that squirts extra fuel as the butterfly opens. I don't think it is a fuel pump because a full fuel bowl will keep the engine running for quite awhile. Good Luck!