1993 Yamaha running too rich

[nacho boat]

I have a 1993 Yamaha 130 hp that after installing a new fuel pump it starting getting too much oil. It is driving me crazy...can't keep plugs in it. It has a sneeze every once in a while which indicates a lean mixture. All of my plugs are black and wet with oil. Motor will stall a little then pick up and go, at WOT it will surge a little bit. If i back off of the throttle to about 4700 rpm it runs smoothly. Does anyone have any suggestions????

 

[jeffersondodson561]

Re: 1993 Yamaha running too rich

I have never seen an oil pump over oil, if your plugs are wet you have a cylinder that is not firing. Comression test, then move onto other diagnosis. Check grounds on coils use a timing light to see if the plug is jumping to gap.