1999 9.9HP no power under way

[pachorr]

Hello all, this motor idles great and revs fine in neutral. When in gear it barely chugs along, almost dies and backfires through the carb from time to time. I have had the carb cleaned and fuel lines replaced. The odd thing is that the other day while under way it all of a sudden ran fine for about 15 minutes. When I dropped the throddle down in the harbor it returned to the same issues. It seems like the fuel/air mix is rich when its acting up. Since it did run fine for a while it seems like if might be something in the EFI...loose wire or bad injector maybe. EFI seems impossible to troubleshoot but I hunting for suggests for what it could be...thanks, Dave

 

[Barnacle_Bill]

Re: 1999 9.9HP no power under way

How was the carb cleaned? Was it taken apart and cleaned properly then reassembled with new parts? Or was a cleaner just sprayed down the throat? That does nothing except clean the throat. Also check for a strong spark at both plugs.

 

[pachorr]

Re: 1999 9.9HP no power under way

It was pulled apart and cleaned piece by piece, jets, floats everything. One plug was a bit wet today so Im changing both just in case. I sprayed carb cleaner down the throat today and no help of course. Pumped the bulp, no change. Idling fine, in gear..no power..exhaust still smells rich. The thing that confuses me is that for about 15 mins on thurs. it ran fine...so im still stuck on some electronic thing..probably EFI...but old school thinking a cylinder is dead or timing is off. Thanks for all your help, Dave.

 

[pachorr]

Re: 1999 9.9HP no power under way

Still not running right....any other suggestions. Thanks, Dave

 

[pachorr]

Re: 1999 9.9HP no power under way

Still not running right....any other suggestions. Thanks, Dave