BOB TEAGUE

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Mercury Max-5 propeller.

Bravo XR Slipping?

Mercury Bravo One propeller.

Dear Bob: I have a 2004 Powerquest 380. It has Mercury Racing 525EFI engines with Bravo XR drives and 30”-pitch Bravo One four-blade propellers. At WOT, I get 74 mph with port engine running 5,200 rpm, and the starboard will rev to 5,800. The paint on the starboard upper case looks chalky like it is running hot. Is there something in the drive that is slipping causing the high revs and discoloration of the outdrive case?

Lee Moore Clyde, OH

Cone clutch and gear.

Lee, while it may be possible for your cone clutch to be slipping, it is unlikely that it could slip that much for very long without causing a catastrophic drive failure. I would drain the oil out of that drive and check the magnets on the plugs for metal parts. If you see particles that are silver, it is likely that a drive failure is in your near future.

Verify that your tachometers are actually reading correctly. This is easy to do with a Scan Tool connected to the data port on the engine. If your engines are stock 525EFIs, the rev-limiter is programed at 5,450 rpm. So, if that is the case, it is unlikely that the engine is running 5,800 rpm. If the ECMs have been modified, then it is possible that the RPM could reach 5,800.

It might be a problem with a propeller. You can try another set or simply put yours on backwards and run the drives in reverse to go forward to see if the problem moves with the propeller. Be careful to remember that your shifters will be backwards. And the boat will handle differently with the propellers spinning in the opposite direction. I have tested several Powerquest 380s in the past. As I recall, the boat is a little faster with the propellers rotating inward, but some docking manners are sacrificed.

Finally, you should have drive showers on your drives if you don’t already have them to help keep the drives cooler.

You might also consider upgrading your propellers (especially if you have a bad one). I would suggest Mercury Racing Max5s that are 15¼" diameter x 29" pitch. I would be willing to bet that a pair of 29 pitch Max-5s would work really well on your boat with significant improvement in midrange efficiency.

Relocate the Mercury Shift Bracket

Dear Bob: I purchased a set of the custom tall valve covers to clear my rocker arms. These are a very nice piece and I love the way they look. However, with this added valve cover height, has anyone had any issues with the MerCruiser shift bracket interfering and being unable to mount to the stock exhaust riser assembly? If so, do you have an offset/extension bracket that can be purchased to raise the bracket assembly up to clear these valve covers? Thanks in advance!

Mark McGahey

It is very common to have the Mercury Shift Bracket not mounted on the engine. More builders than not routinely install the Mercury Shift Bracket on a stringer along side the engine or on the transom.

In your case, find a place where the Mercury Shift Bracket can be installed where the cable easily reaches from the helm and the drive. Usually, if it is mounted on a stringer, #14 stainless steel truss head screws are used with silicone sealer.