Volvo Penta DP290 and AQ271C

[erikapeterg]

I have a 25 ft boat (Cruisers Barnegat 2530) weight unladen 4,400 lbs, Max revs per Volvo 4,600. Currently it has a pair of A6 duoprops. I have been told these are basically intended for low revving diesels. The boat is very slow to get on to the plane and last time out only revved at an indicated 3,500 rpm and indicated speed 25 knots.
Could anyone please advise me as to whether the props are the correct ones for the boat and if not what should be fitted?
I have been told that the Cruisers foam flotation system could be waterlogged causing a dramatic increase in weight.
Can anyone advise could this be true?
Any help much appreciated
Thank you
Regards
Peter

P.S. I am 72 and last boat was in 1964 an 18 ft Owens Kent with twin 50 hp outboards, have I bitten off more than I can chew - I wonder..........

 

[Maclin]

Re: Volvo Penta DP290 and AQ271C

The A series and B series have the same pitch regarding the numbering. The A series are thicker and also have a 4 blade as the rear prop. With an AQ271C your boat should really have the B series props on it. This is assuming the drive ratio is the 1.95 and not a 2.32 which is what some smaller diesels came with.

Regarding what B series, i.e. B4, B5, that is the question.

A move down in pitch seems to be indicated based on the rpm's attainable now with the A6 set.

Regarding the waterlogged foam, I would be surprised if it has the foam in a 25 foot cruiser. The 4,400 pounds seems reasonable for a boat that size, depending on how accurate the weight figure is.

I think a B4 set would be good. I do think the engine may be a little tired so it would be good to determine the health of the engine with a compression check. Also a good tuneup may be in order, cap rotor plugs and filter.

If the engine is in good health and tune then a B4 set should be able to let the engine hit 4200-4400 at about 30mph or 25 knots. This is more of a guess than fact, I am basing this on the numbers you are getting with the A6 set right now.

 

[Scott Danforth]

Re: Volvo Penta DP290 and AQ271C

you should be running between a b3 and b5. my friends 25' Carver Montego (27' overall) is running B3's with a dry weight of about 6000. I am running B6's on my Cruisers Rogue with a dry weight of 3600.

if you were local, I have a set of B5's you could try.

also, check the timing advance. I myself am having issues with the original distributor in my 271C.

 

[erikapeterg]

Re: Volvo Penta DP290 and AQ271C

Hi Scott, thank you for your reply. I would gladly pay return carriage to borrow your B5's, quite happy to give a deposit too, it is so expensive to buy a new set of props just to try!
If it is of any help to you I have the original distributor and coil from my AQ271C, a recent buy and try that made no improvement and ?310 worse off! (left replacements on the engine - no point in changing again).
Please let me know.
Regards
Peter
P.S. Forgot to say we are not exactly local we are in Llangrannog, Wales, UK

 

[Bondo]

Re: Volvo Penta DP290 and AQ271C

Hi Scott, thank you for your reply. I would gladly pay return carriage to borrow your B5's, quite happy to give a deposit too, it is so expensive to buy a new set of props just to try!
If it is of any help to you I have the original distributor and coil from my AQ271C, a recent buy and try that made no improvement and ?310 worse off! (left replacements on the engine - no point in changing again).
Please let me know.
Regards
Peter
P.S. Forgot to say we are not exactly local we are in Llangrannog, Wales, UK
(petergostelow@hotmail.com)

Ayuh,.... Welcome Aboard Pete,... Please read the forum rules,...

postin' yer email address is against 'em...

No doubt in my mind, yer props are the problem,...

Runnin' that motor, at those loads, 'n rpms, will burn a hole in a piston, in a Hurry....

Find some different props....

 

[Scott Danforth]

Re: Volvo Penta DP290 and AQ271C

I would suggest checking with your local marina and prop shop. many have props to lend for determining the right combination. however if your only getting 3500 rpm, I would suggest B3 or B4's