cavitation?
 

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i know this is cavitation caused, but why and how to fix it? these props are new with only 30 or so hours.

I forget is your boat a single or twin.
If twin you might be crabbing the drives.
It looks to me like you have cavitation on the back side of the drive in front of the prop but only on one side.

twins. both props have the same pitting. have not checked the drives for toe but the only thing different from years past is im now going 30 plus mph faster. i also get a slight vibration over 90 mph.

If you are spinning the props out than the front of the drives should be 1/8 to 1/4 inches farther apart than the center of the prop shafts.
The opposite if you are spinning them in.
If you are crabbing the drives that could cause that burn and the vibration.
On my Scarab I noticed a big difference when I got it right.
You will have to play with the distance - IF you go too far you will feel it.
I should say that I could feel it.

Is the pitting on the other prop on the other side of the drive.???

How deep are your props?

i appreciate the response. boat is in storage til this weekend . i'll check those things out.

i am spinning them out. drive height is whatever saber set them at new. i dont think they are high especially be todays standards.

drives are toe in about a fat 1/16 inch. looks ok to me.

Adjust the drives so the nose of the drives are 1/4 inch farther apart than the prop shafts.
You are toed in - You should be toed out.
Props spinning out force the back of the drive to the outside.
You have to toe the front of the drives out to counteract this outward force.
You will have to find the sweat spot.
But when You get it right I bet you will gain at least 1 MPH and the cavitation will mostly go away.
I could feel the change in handling on my SCARAB when I got it right.
You are crabbing your drives through the water.

If you want me to meet you somewhere I will help you dial it in.
Steve.

well dont i look stupid, thought you needed them toed in like on a car. could this cause a vibration when im near max speed?

thanks , i appreciate it. im heading to elk /torch lake for the week. i'll try adjusting it tomorrow before i go.

very much so.
You will have to play with it.
It depends on how much give you have in the bushings.
Try 1/4 inch out and I think you will be surprised at the difference.
Keep trying out 1/8 inch at a time.
You will know when you went too far.
1/4 inch is a good starting point and I think that is where I had my drives on the SCARAB.

ok, set the toe. but the vibration is possibly getting worse. is there supposed to be any play moving the prop shaft vertically?

No.........NONE

are these bearings tapered or im guessing not since there is no end play? im guessing that this is the cause of my vibration over 80 mph?

A Bravo should have Zero propshaft play , Vertical or Horizontal . If you do .... you have drive issues.

i'm guessing about .010. lateral movement. also there is definitely a tight spot when turning to props by hand. guess im rebuilding this fall.

I should have said Axial or Radial ,,, In and Out , or Side to Side .
Man if it does I'd be checking the magnets for metal. You dont want to push your
luck and cost a bunch more money.

they are clean. the only other thing a did on someones advise was to swap drives side to side last year went i put the new engines in. or is it just time with 1k hours behind some 454 mpi's.?