Cavitation Issue
 

Hi Gang

I have a 1995 34 Powerquest with 454 mags and Bravos.

The boat has 460 hours.

Here's my issue. The port side is cavitating upon launch (easy, mild or hard). Just started and does not do it all the time. I never get cavitation after being on plane. Today I launched 15 times. All easy to medium. Also tried the tabs down with varying RPM and no issues. Likely 50% of the time I got a rostertail from the port side.

The drive and prop look ok. I don't believe it is the hub giving way as I am getting a lots of white water when it happens. If it was the hub or drive I presume I would get lots of motor noise and propolsion evidence on that side.

What could be causing this?

Thanks!

Jeff

To me rooster tail = drive not in tucked position. Did you check if drive is in fact down when this happens?

I thought about that as well. I raised and lowered the drives to be sure they were working and triple checked that they were down (tucked).

The other symptom is that it does not cavitate immediately....when it happens it happens after a bit while I am coming up on plane.

Thanks

Jeff

When it happens throttle back, do not touch the trim, and inspect drive position. If the other drive (not rooster tailing) is not raising at same rate (bad seal/s) it may point to wrong offending drive. Just a thought.

That's a good thought. But in all cases the drives were fully down. This is not happening while trimming the drives....when they are fully down while coming up on plane.

J

Guys,

Upon reflection I wonder to what extent having NO gas in the boat is causing this. Ok, maybe 10 gallons. This would cause the arse-end to be lighter and since I don't launch with tabs I wonder if this is provoking the issue? I usually keep minimally 1/3 tank.

hmmm