Re: Losing drive at high revs.
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Originally Posted by
moresparks
Hi I am looking at pointers at this early stage and would appreciate any suggestions.
I have a pair of AQ171’c on 290 SP-A drives. All season things have been fine so this is a sudden development on one drive.
At no wake zone things are fine and I can travel all day at 2000 revs, but the moment I push the throttle forwards to get on the plane one drive seems to lose drive around 3500 revs. Similar to suddenly going into neutral. Throttling back to displacement speeds and things are all fine again.
It is possible that the prop hub has let loose. In other words, the inner hub is spinning within the outer hub.
Draw a line through both, and test it. If the line shifts, the hub is failing.
Or..... install that same size/same pitch spare prop that you have on board! (you do have a spare..... right?)
I have not had a chance to lift the boat out yet so cannot tell if there is water in the oil, not sure if this would cause this problem.
It's time to do so!
I replace the bellows every other year and undertake a pressure and vacuum test.
The vacuum test can be performed with gear oil installed. However, the pressure test requires that the gear oil be drained.
The propeller is only a season old.
The trim meter doesn’t seem to change as far as I can tell.
Is this a symptom of the cone clutch?
What gear oil are you using?
If it is; can these be repaired or do you have to buy the complete gear set?
While Volvo Penta makes no mention of this, an experienced tech can lap the components renewing the function.... if they are OK to begin with, but perhaps glazed a bit.
Is there any checks I can do whilst it’s in the water or is this season end??
I would certainly pull it so that several things can be looked at.
Rick ... aka Ricardo..... AQ series Volvo Penta repair
Portland, Oregon
28' SDN F/B w/ twin Volvo Penta 5.7L DP's
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