i posted a little about this in another thread but
i will be more specific

i have a 27 powerquest w/502 mag bravo 1
just had outdrive rebuilt two weeks ago
while i am still in the break in period i am not
going wot the problem i was having was while taking
the boat to 3000 rpm to get on plane everything was normal
but when i try to go from 3000 to 4000 the engine over revs
tack goes way up but not the usual traction today i tried it again with the same result when i got home i removed the prop and the hub insert which was plastic and octogon shaped there was a fingernail sized crack about 1 nich long
but was not a through crack also nooticed a little play while inside the prop housing and a little play with the other plastic gear housing (tell me this is the problem i will be very
happy) and is it unusual at getting on plane not to slip or is it a direct result of the higher torque at the higher rpms

sounds like it, did you check the other end where the castle washer is bet you its stripped out!!!!

actually its not it has a little slop when inserted into the hub but thas all gears look ok on castle insert and inside hub
could the hub flop around on its octogon sides on the inside of prop?

It's possible, Merc sells a part to stuff in the back end of those plastic hubs, or you can try a new flo torque hub. Sounds like it's either the hub or your coupler. I would replace the hub first and see if it fixes your problem. Hopefully it's not your coupler. I have a couple of extra hubs, if you need one.

502 should have a steel hub not plastic, i don't recall the part# but have them on the shelf call and i can send you one out 606.561.7115

bad kachina: replaced the coupler last year
better not be that

if the coupler was a steel insert how would it break away
or would the castle just break (sorry the castle is steel)

mine looks like this

http://www.outdrives.com/props/flowtorque2.html

Sounds like it's more of a prop ventilation issue than a hub problem. If the plastic hub had spun you would find a melted pile of goo in place of what used to be the plastic insert.

The plastic hub is designed to fail just before the propshaft does. It's stronger than given credit for. It you have a problem spinning the plastic hubs then go to the solid insert. The plastic hub affords protection to your drive while the steel insert does not.

The crack you noticed is normal wear for the plastic insert.

Matt

thanks matt for taking the time to talk today
i replaced the hub inside prop and im still seeing same result
as before im going to do one more thing disconnect drive shower one more thing when i put the boat in gear should i be able to rotate prop (because i can) in one direction

that was it i had a gaffrig drive shower installed
when i removed the pickup hose - problem solved
no more cavitation problems (but now i have no drive shower)
has any body else noticed these problems with their drive showers mine was the square plate gaffrig with single pickup
hose and we used the template to install in correct location

sounds like you need a stainless high torque hub insert.Give me a call and I will give you one ,just pay Fed -ex shipping,maybe you have an account you can use?.Fri would be best. Hopefullly this will do it,if not ? see an outdrive specialist. Good Luck Darin! it possibly could be the prop,I wouold have to take a look at it to tell,also s little slack is normal,correct me if I am wrong.