redfountain420s

ok i thuoght this was a solid hub but it looks like a pressed in hub ------- prop is a hydamotive q4 25 pitch 4 blade, boat 1988 40ft fountain 10000 lbs star side when i get on it 5000rpm 5lbs boost all of a suden motor revs like its in neutral back down throtle and it grabs again. it just started doing this ive only got 10 hrs on it since repower. it doesnt do it geting on plane or mid range. water was flat. can this hub spin what do you think
thanks kevin

redfountain420s

what thrust washer should i be useing with this prop

throttleup

The hub is welded in. From your photos it doesn't appear as if the weld is broken. If the weld is broken you would be able to move the hub around inside the prop.
To mount the prop you need the following parts; thrust washer
12-835467 1 or 12-835467 5. On the aft end of the prop you need; 12-31211A3. Then the lock washer and nut.

Some dynamics have changed since the re-power, which is causing the prop to ventilate. What was the horsepower before and after the re-power? Do you have dyno runs on the new motors? What is the WOT rpm and speed with the new motors and the old motors?

Matt

redfountain420s

thanks for the response matt, i think its posible its the trans after a little more investigating , i can barely turn the propon that side and i pulled the drive and it turns fine at first i saw a spot where the prop rubbed and thought thats why it turned hard i put the drive back on and its very hard to turn. i guess i was hopeing for the easy way out.
to answer your other ?s
stock power merc 420s same trans and drive 21pitch 3 blade 5200 rpms 62mph
repower 2000 merc hp500efi long blocks B+m 420 mega blowers 750holleys still fine tuneing but star 5300 rpm 5lbs boost, port 5000 rpm 4lbs boost 76mph

redfountain420s

heres a better picture ,do you think the clutch pack could be slipping in the trans , would it grab again after letting off. i went with stock trans because over budget already. what fluid do you use in borq warner trans? thanks again Kevin