1985 Evinrude 175 h.p. outboard motor factory installed on Baja ski boat. Run the boat down lade for 20 +/- minutes then turn motor off and sit for 30 +/- minutes and then start motor and attempt to pull skier up and as soon as we floor it wide open it bogs down. We try this a couple of times to no success and then tell skier to drop rope and we run boat to lake to blow it out. We then come back and can successfully pull skier up. We want to describe as loading up or running too rich. The VRO (variable ratio oiling fuel pump has been removed). We now mix the oi at about 30:1 ratio. This is happening on a routine basis and interested is how to fix. Any suggestions would be appreciated. Thanks!