Opinions please...KAD42 with douprop
- Thread starter Pearl dog
- Start date
Charlie415
Crew Member
If looked after should see 4000+ hours of economical reliability. Parts are more expensive than gas.
Oly1
Well-Known Member
If they are well looked after hours and it will will be a proper fit for your boat then I would consider it. Diesel is cheaper than gas at the moment by quite a margin and better fuel mileage. However the oil companies whims may and probably will change in the future changing it back to the way it was. Charlie is right in that diesel will cost more to fix, but is way more economical in the in between maintenance times. It really comes down to personal preference and how long you plan on keeping the boat and motor and how many hours a year you plan to put on in a year.
A lot of people pod these boats and put outboards on them, then there are the devout diesel guys. Depends on which guy you want to be.
Oly
A lot of people pod these boats and put outboards on them, then there are the devout diesel guys. Depends on which guy you want to be.
Oly
Great engine. Lot's of raw water cooled stuff (turbo, oil, exhaust) that are very prone to corrosion - I am in the middle of replacing my 1992 TAMD 41's with outboards as corrosion killed them.
At planing speeds, fuel usage is similar to gas. At slower speeds (up to hull speed) diesel is many times more economical.
At planing speeds, fuel usage is similar to gas. At slower speeds (up to hull speed) diesel is many times more economical.
Pineapple Express
Well-Known Member
I'm guessing you're looking at this boat?
https://vancouver.craigslist.org/rch/bod/d/richmond-monaro-27-hard-top-1996/6885313682.html
https://vancouver.craigslist.org/rch/bod/d/richmond-monaro-27-hard-top-1996/6885313682.html
scott craven
Well-Known Member
Nice boat, $70 k though ??
Pearl dog
Active Member
Gong Show
Well-Known Member
It's a good engine. Interesting placement is the water strainer above the alternator.
Check the supercharger oil. The electric clutch on the supercharger is worth looking closely at. Oil cooler is another thing to look at. That being said, I've put thousands is hours on one and it has never stranded me.
Check the supercharger oil. The electric clutch on the supercharger is worth looking closely at. Oil cooler is another thing to look at. That being said, I've put thousands is hours on one and it has never stranded me.
Charlie415
Crew Member
On mine the super charger is bypassed. I was told by my mechanic that unless it was needed for hole shot it was a pain. I believe supercharger kicks in about 1700 rpm and the turbo about 2300. I have a bayliner 2850 and it gets out of the water without the supercharger. I have thought about hooking it back up but have not really seen the need.
Pearl dog
Active Member
It seems the 42 gets the most “negative” reviews because of the supercharger, turbo combination. It’s the first in a very successful line of marine motors so It’s natural that the ones that followed benefit from improved technology etc..
I’ve heard that people disconnect the supercharger as has been mentioned. Not sure if this one has had that done or not. I’ll try to find out.
What about the Duoprop? Seems to be a very complex piece of machinery. Almost fragile looking with all those moving parts. What’s the big advantage of it?
The fact is the unit is 23 years old and has 1100 hours. Obviously it works. I’m just trying to take advantage of all the knowledge on this forum before I make any decision. Thanks for the reply’s so far.
I’ve heard that people disconnect the supercharger as has been mentioned. Not sure if this one has had that done or not. I’ll try to find out.
What about the Duoprop? Seems to be a very complex piece of machinery. Almost fragile looking with all those moving parts. What’s the big advantage of it?
The fact is the unit is 23 years old and has 1100 hours. Obviously it works. I’m just trying to take advantage of all the knowledge on this forum before I make any decision. Thanks for the reply’s so far.
daddystoy
Well-Known Member
Volvo penta came out with the duoprop in the early eighties. If you look at a schematic of the two counter rotating shafts it's amazing in its simplicity.
Pro's according to Volvo, better fuel economy, better acceleration, faster top end, straighter tracking
Con's would be props are expensive. Any potential maintenance and repairs will be more expensive than a single prop drive.
As long as the drive can handle the torque from the diesel you should be fine.
I'm sure there are other guys on here that could chime in with some first hand experience.
Pro's according to Volvo, better fuel economy, better acceleration, faster top end, straighter tracking
Con's would be props are expensive. Any potential maintenance and repairs will be more expensive than a single prop drive.
As long as the drive can handle the torque from the diesel you should be fine.
I'm sure there are other guys on here that could chime in with some first hand experience.
Gong Show
Well-Known Member
Get the maintenance records for the engine.
The 43 was problematic, trying to pull too much hp.
Supercharger is nice. It is controlled by an electric clutch, I don't think the clutch is fully marinized. I treat it carefully, like an alternator.
Pressure test the coolant system.
Duo pro is fine. Don't hit the continent with it, it will lose. The bellows on the leg are perishable.
The 43 was problematic, trying to pull too much hp.
Supercharger is nice. It is controlled by an electric clutch, I don't think the clutch is fully marinized. I treat it carefully, like an alternator.
Pressure test the coolant system.
Duo pro is fine. Don't hit the continent with it, it will lose. The bellows on the leg are perishable.
daddystoy
Well-Known Member
True about the U-joint bellows. Volvo recommends they get changed either yearly or every other year. It varies on drives. They can be a bit of an Achilles heal for the drive but generally not a problem.
The changing them out regularly I feel is not because they are "worn" out but more just to check for leaks as well as lubricate the u joint bearings. Also it prevents you from being "That Guy" That doesn't remove his outdrive for years and when the time comes to take it off because now you do have a problem.... well good luck. That is when the " fun " starts!
The changing them out regularly I feel is not because they are "worn" out but more just to check for leaks as well as lubricate the u joint bearings. Also it prevents you from being "That Guy" That doesn't remove his outdrive for years and when the time comes to take it off because now you do have a problem.... well good luck. That is when the " fun " starts!
BCI
Well-Known Member
My experience with the diesel inboard outboard has been different. I run a single volvo D6 400hp in my Eaglecraft. She is about 18,000 pounds and at 30mph I am burning 16gph total. In order to do that with gasoline outboards, I would require 2 x 350hp and I would be burning 32 gallons per hour. My diesel uses half the fuel that gasoline outboards would use at planing speed and the diesel fuel is much cheaper to purchase.
I used to run 2 x Volvo D4-260hp diesels in my ocean sport and at 30mph I was burning 14gph combined.
I run 2 x Verado 300hp on my Whaler 315 and at 30mph I am burning 25 gallons per hour and she is same beam and mass as the Ocean Sport was.
I have run 2 x F225 on a Grady 282 Sailfish and at 30mph I was burning 20-22 gph.
The diesel is much more efficient and that translates to a much lower operating cost for fuel, and huge range versus running gassers off the same size tankage.
Last edited:
