Advice on converting a 280 out drive to a duoprop.-gctid803308

[Guest]

I have a 83, 28' bayliner with an 280 outdrive that continues to give us troubles, mostly with reverse.

Are there suggestions on going to another outdrive variant? The boat is only single engine and for the size of the 28' boat is underpowered. On the surface we were thinking that going to a duoprop might solve several problems.

Please advise if possible, thx.

[Download_Complete]

And to answer your question, in this boat I would not replace the drive with anything but another Volvo Penta, for reasons of smoothness, and also ease of swapping on the DP.

You will lose that with literally every other option (Merc especially, unless you swap to a Bravo...which will be BIG bucks).

[2850Bounty]

"Download_Complete" post=803372 wrote:
And to answer your question, in this boat I would not replace the drive with anything but another Volvo Penta, for reasons of smoothness, and also ease of swapping on the DP.

You will lose that with literally every other option (Merc especially, unless you swap to a Bravo...which will be BIG bucks).

[color]#000088 wrote:
Not to mention that the structual transom will require "in-filling" in order to accommodate the smaller Bravo gimbal housing. [/color]

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[Guest]

Very good information and clear advice. I think after reading your reply and the others it would appear that replacing the lower with a duoprop would be the best case along with fixing the latching mechanism.

I noticed in an earlier conversion post, on this site, that someone who also had a 28' Contessa went to B2 as opposed to the B3 or B4 prop.

Thanks again for the advice, I guess the next step is to start searching for a Volvo duoprop conversion kit...

[Download_Complete]

First off, the reverse latch is (or should be) a really easy fix that will solve your reversing problem. You really need to fix it anyway, since it can cause transom shield damage which is MAJOR bucks to fix.

Second, the DP lower is easy. You just need a DP lower unit in a 1.95 ratio, and props. Take the boat to a VP mechanic who can swap the lower on and do the proper shimming technique. The DP conversion is literally a bolt on, as opposed to repowering which will be a major project. Here, see for yourself:



This conversion is easily worth swapping in a bigger engine in another power system brand (like OMC).

The problem you will have is actually finding a good DP lower for a good price. The 1.95 ratio is far and away the most popular, and coupled with the limited # of boats in the 1980s and 1990s that got one, the supply out there is tight and getting tighter every day.

[Download_Complete]

Rick can tell you for sure, but this might be what you need:

http://www.ebay.com/itm/Volvo-Penta-DP-D-Rebuilt-duoprop-outdrive-lower-gear-unit-1-95-V8-gear-ratio-/172619071718?hash=item2830e600e6:g:TLsAAOSwax5Yq0xB&vxp=mtr

[2850Bounty]

Repairing the reverse latch system may be quite involved... depending on what is wrong with it!

However, once the gear oil has been drained, the s/p lower gear unit removal and the Duo Prop lower gear unit installation should require no more than 3 hours..... including the calculations and re-shimming of the race.

Don't let any shop tell you differently.

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[Lorimer]

I have a 1984 contessa fly bridge with a 280 upper and a 290dp lower. We recently repowered with a sbc with 280hp.

Our props are new vp b2's and 4200rpm is the max wot we achieve. Weight might be a factor with 4 golf cart batteries and 2 starting batteries in the engine bay.

I'm considering removing 2 house batteries, if that doesn't help I may repitch the b2's to pick up a couple hundred rpm.

Regarding the reverse pawls I need to thoroughly clean/remove even the smallest of muscle and barnacle growth 2-3 times a season from the entire assembly by hand while in the water.

[Guest]

Thanks everyone for the information on this topic. As a postscript to this thread we stayed with the 280 for the time being, as the cost was fairly high to convert to the duoprop.

We had the out drive serviced and the reverse problem has been taken care of, I won't go into detail on that part.

Hopefully we will make it through the season without any other major issues coming up.

Thanks again,

J. Eckland or JPKKECK

[2850Bounty]

Just out of curiosity...... what were you quoted for the DP conversion?

How much for a DP lower gear unit only?

How much for the removal of the s/p lower, and the re-shimming and installation of the DP lower?

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[Guest]

We were looking at over 2K just for the reconditioned lower unit. We never got to the point of getting estimates on the install etc.