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| Questions on prop size and Volvo 280 ... |
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Mike
Member
Username: mrmahi
Post Number: 9
Registered: 04-2009
| | Posted on Wednesday, September 09, 2009 - 03:12 am: | 
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I have a question concerning props and RH/LH rotation. I have a heavy (6000 lbs) 24 foot GlasPly that gets very unpredictable going downsea. It seems as though I have no steering when going down big swells...and sometimes seems downright dangerous. I believe it is too rear heavy, as I had a friend in the cabin and it seemed to even out things a bit. Trim tabs are up going downsea. I have the outdrive positioned on the inside (transom side) pin.
I have found the 16x15 LH prop is a little too much..the 16x17 LH seems to hold the rpms down and still not load the motor, so I think I have found the right pitch, but I wonder if rotation change will help. Again, the rear of the boat is heavy as I have added a 25hp kicker, fuel cell, and a swimstep, and the kicker is on the drivers' side so it is definately heavier on that side.
Would a RH prop be a bad choice, as I am having a problem with going into reverse...it bangs loudly? I have checked the shift linkage and other things and have concluded it is the nut on the top gear shaft having too much clearance at .026" The specs are between 004 and .020. I was wondering if the copper washer inside the outdrive gears will have an effect on that? The reason I ask is that it has a crack in it, but is still in tact. This ths the copper washer that is pressed (I think) inside the gears. There is no part # for it, so I think it is part of the gear unit. Everything else looks good inside the drive..gear pattern etc. I am going to get a proper size nut and see if I can make up the slop. BTW, I am running an VP AQD40a 138 hp. Any advice would be appreciated.
Aloha,
MIke |
Morten Ringvold
Senior Member
Username: haffiman37
Post Number: 4207
Registered: 04-2006
| | Posted on Wednesday, September 09, 2009 - 03:35 am: |
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A RH prop may make your boat tilt to STB.
The reason for the out of spec clearance on the top nut is most likely wear in what is called a 'wear ring' at the bottom of the vertical primary shaft. It is a brass ring locked with two 1/2 ring steel pieces.
Unscrew the top nut (note it is links thread), and drop down the shaft.
Change the wear ring, re-install the shaft with original nut and re-measure.
The more play you have in the vertical shaft, the bigger the 'bang' when shifting! |
Mike
Member
Username: mrmahi
Post Number: 10
Registered: 04-2009
| | Posted on Wednesday, September 09, 2009 - 04:10 am: |
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Thank you Morgan! So the copper washer should be OK inside the gear? Forward gear is fine while shifting....just reverse bangs...in fact, I dont use it at all...just turn the boat around to launch.
Sounds like I need a left hand 16x17 then.
Thank you again... |
Morten Ringvold
Senior Member
Username: haffiman37
Post Number: 4208
Registered: 04-2006
| | Posted on Wednesday, September 09, 2009 - 04:45 am: |
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Sorry, LH will let your boat list to STB!!
As for pitch, the one that gives you 3600+ at full throttle (AQD40). |
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