View Full Version : Marine Power

07-08-2007, 03:06 PM
"I have twin MArine Power 350 Efi engines. Last year when I ran the boat at 3200 to 3400 Rpms everything worked great. However, If I bumped the Rpms to 3800 to 4000 Rpms the Port Engine would loose power and the tach would jump while the temperature gauge would climb to around 210 degrees. Now this year both engines are having the same problem even at 2000 Rpms. I have changed both water pumps and changed both fuel filters. If you can help I would appreciate it"

09-19-2011, 07:02 PM
we need some info how many hours on engs? it sounds like you could have a few thing going on if doing 3800 and the tack starts to jump you could be looseing ignition? the tack works off the minus side of the coil over heating is some thing different i would get a laser temp gun there pretty cheap and test the boat with the gun while running 3800 or even less see what heat you have at the risers manifold the block themostat housing the risers should be about 100 degrees aprox is this fresh water cooled? if so is it just the eng witch would a 1/2 system meaning the mans and risers are salt water cooled? also i would do a compression test? make sure its good like i said we need more info?

09-20-2011, 10:17 AM
check the water hose from oil cooler to water pump if there is no spring in them they could be colapsing

my engine did same changed hose runs cool now