Standard Bravo 3 showing wear
 

Running a standard Bravo 3 @ 2.0 ratio behind a single 502 cuin 415 HP in my Formula. According to what I've found the standard B3 can handle 400 HP. Had the drive gone through 4-years ago because it was make more whine then I was use to when idling. Rebuilder (Certifed Merc tech with his own shop) found nothing out of tolerance. My previous B3 never made the noise and I still have it, but it is old style with added piece on the rear (B1 with a tail) for B3. At the end of last season found a bit of foreign matter in the lower section of the drive, found nothing in the top. Material was showing the slightest bit of gray in the lube and could see very fine particles a metallic substance. Drained the lube for 3 days and then refilled.

Pulled the plugs this season and found the same similar issue with slight gray in the bottom and green/black in the top. My rebuilder is gone and therefore I'll be taking it to someone else so hence the question.

I don't see this as to much HP for the drive maybe something else, any points should be checked?


Specs: WOT 5150 RPM, 24 pitch props

Most Bravo IIIs have problems with the pinion gear in the lower. Its a pretty small gear that has to run to larger grears and the hardness wears off quicker and this creates the gray oil and all that mess goes through all the bearings. Thats usally the first thing I check on a bravo III. How many hours are on it?

I bought it from a dealer in CA which said it was a customer pull off because there was something the customer was questing. Dealer said they took it apart and found nothing. Don't know exactly but the bar code labels were still on the drive, so Iguess so far around 150 to 200.

Unless you're at a very elevated lake I have the feeling that the 2.0:1 ratio will be a little hard on the interals. I would take the next opportunity to change to 1.81:1 or 1.65:1.
Lower ratio and higher prop shaft speed is easier on the internals.

The boat originally came with a 7.4 pushing the 10K pound boat and didn't have enough power to get it up most time. A 24 pitch prop turning 2600 rpm, 2872 at 1.81 and 2872 at 1.65 respectively. Boat handles pretty well at idle rpm for docking and doesn't move very fast. Moving to 20 or 17 pitch props will slow the boat down further, do you see any problems with being unable to move enough water to dock without revving the motor?