NW Redneck
Chief Petty Officer
- Joined
- Jul 30, 2006
- Messages
- 643
1975 OMC 175(Ford 302)
99.9% of the time the engine runs just fine. Top speed 42-43 mph, proped for 4100-4200 rpm wot as per manual, oil pressure steady @ 50psi, temp steady at 160*. Sounds nice and smooth.
Three seperate times now after running for approx. 35-45 min at about 35-38 mph, the engine starts to drop RPM's in a 'surging' pattern. If left alone, the RPM's keep dropping lower and lower at each dip, sort of 'down 3, up 2'. If I pull the throttle back to idle for a min, then come back on plane, it runs just fine again. Each time this has happened we have been heading to our cabin on a local lake. It happens about 3/4 of the way there, so we're only about another 10-15 min away. First two times was on the way up, the last time was on the way back. The incidents were seperated by weeks to months, so I'm not sure where to start looking . Any suggestions from the iboats brains?
99.9% of the time the engine runs just fine. Top speed 42-43 mph, proped for 4100-4200 rpm wot as per manual, oil pressure steady @ 50psi, temp steady at 160*. Sounds nice and smooth.
Three seperate times now after running for approx. 35-45 min at about 35-38 mph, the engine starts to drop RPM's in a 'surging' pattern. If left alone, the RPM's keep dropping lower and lower at each dip, sort of 'down 3, up 2'. If I pull the throttle back to idle for a min, then come back on plane, it runs just fine again. Each time this has happened we have been heading to our cabin on a local lake. It happens about 3/4 of the way there, so we're only about another 10-15 min away. First two times was on the way up, the last time was on the way back. The incidents were seperated by weeks to months, so I'm not sure where to start looking . Any suggestions from the iboats brains?
