As seen in Speedboat Magazine’s
June 2024 Issue.

502 Mag to 525 EFI

Dear Bob:
I have a 2000 29 Fountain with a Mercuiser 502 Magnum that has been damaged by being frozen. I am getting ready to swap the motor and install a 2004 Mercury Racing 525EFI that I purchased which has been recently rebuilt. What concerns should I have with this motor swap? Is the wiring harness and mounting the same for both motors? Please provide me with any information you think would be helpful. Thanks!

Charles Miller
Sandy, Utah

Continue reading →

As seen in Speedboat Magazine’s
April 2024 Issue.

TOE-IN OR OUT?

Dear Bob:
Can you explain the correct procedure for setting the alignment of the drives on a twin-engine boat? I would think that if it is not in correct alignment, you could be scrubbing off speed. On a car, there is a certain amount of toe-in, when the car starts moving, that position likely will change slightly. Is a boat the same? Does the procedure change with regard to the direction the props are turning?
Thanks!

Randy Hallman
Page, AZ

Continue reading →

As seen in Speedboat Magazine’s
March 2024 Issue.

OIL PRESSURE ISSUES

Dear Bob:
I have a 39 Cigarette Top Gun with Mercury Racing 700 SCIs. I recently had the engines completely refreshed. At idle on initial startup, both engines maintain 60 PSI on the oil pressure gauge with no fluctuation in pressure. One engine has an issue with oil pressure when it goes above 3,000 rpm. Above 3,000 rpm, the oil pressure drops down to around 15 psi. It takes about 1 minute for it to drop from 60 psi to 15 psi, and the drop is linear. It will stay at 15 psi until the engine goes under 3,000 rpm, and then returns almost instantly to 60 PSI. The water temp on this engine does not get over 180 degrees. In order to validate the electric oil pressure gauge, I placed a mechanical gauge on the engine and was able to replicate the problem. The engine does not use or leak oil. The engine runs smoothly and does not make any unusual noises or knocks. I have concerns about oil pressure being low on high rpms.

Any help would be greatly appreciated.

Bob Campbell
Houston, Texas

Continue reading →