Volvo Dup Prop

Just got a boat with a Volvo 305 and duo prop out drive installed.

Any suggestions for a long and happy life? Weak spots , things to watch?

Max RPM for extended cruise? 3000-3200 seems nice ,
but for a diesel guy its about 2x the RPM I'm used to.

TIA, FF

 

The RPMs depend a lot on your boat. Change the gear oil regularly and do a pressure/vaccum test. Also, remove and grease the splines on the props once a year.

 

Cruising on gas is that not more like 4200rpm?
As for the props, dont bent or loose then, and tell us how you like the volvo CR props

 

I've got a AQ271 VP with the DP290 DP. We normally cruise around 2300-2400 RPM which gives us 22-23 kts. Wide open is 4500 at almost 40 kts. Took awhile to get the correct props dialed in.

The most important ($$$) lesson I learned owning this setup was to change the drive and exhaust bellows every two years.

The reverse latch is a bit of a bugger to get working right. Make sure it's clear of all paint where the latch catches the drive.

Docking a single IO is a bit of a chore and takes practice. Ours backs well to stbd but is a slug to port, dunno why.

Don't ever operate the drive above the beach limit setting. You'll rip the drive bellows open.

I've been able to R&R the drive myself which saves a bucket full of money. Not a job anybody can do alone. I made a lifting rig that hangs on my swim platform to help.





A well maintained DP is a thing of beauty. Well maybe not beauty but a very nice piece of equipment.

 

"Cruising on gas is that not more like 4200rpm?"

WE only get 4200 at wide open throttle , will look at linkage and do a tune up.

But the boat is fine at 3000 , good attitude and helm response.

AS an old sailor 25K is so much quicker than 6.5K , it is fine for us.

Any more tips???


FF

 

Just experiment Fred. Eventually you'll find the "sweetspot" where the boat likes to run.

 

Eventually you'll find the "sweetspot" where the boat likes to run.

Will take a while as this has no Flow Scan for instant fuel use comparisons.

Guess the old "how goes it" graph and pencil will be making a comeback.

 

Duoprop etc should be treated similarly to other Sternlegs and transmissions for long life.
The first service (lube) and proper run in are crucial to allow EP additives to properly condition contacting surfaces as they wear in.
If cruising is the objective then make sure you don't over load the unit at lower rpm's especially if changing the props to suit the cruising speeds. Excess torque will destroy them faster than you could imagine.
NiK

 

"If cruising is the objective then make sure you don't over load the unit at lower rpm's especially if changing the props to suit the cruising speeds."

WE will be cruising in mostly open water with no speed controls.

So what ever speed we get at a nice "sweet " RPM will be comfortable, no Cruising Props changeover.

FF