Mustang 3800, Riviera 370, Sunrunner 3700

[FraidNot]

Any owners out there?
I'm researching cost of ownership and any advice from owners/users most welcome.

[Sandyh]

We had a share system with an M370. Can I help?

Cheers ;

[FraidNot]

looking at a 5 year old boat with (typically) 6.2 mercruiser - one point of advice I have is to inspect and probably replace the risers upon purchase - and to do a full leg and engine service at that point.
Do you recommend:
- annual slip and leg/engine service, (if conditions allow)
- bi-annual slip with full leg service? (engine at 100hrs)

Also - what cruise speed and fuel flow did you get (if you recall) ?

Any advice most appreciated

[JJB]

Originally Posted by FraidNot

Any owners out there?
I'm researching cost of ownership and any advice from owners/users most welcome.

We have a Sunrunner 3700 back at home. It has the usual mechanical servicing every year, which varies widely depending what needs to be done according to the service schedule. It's a fantastic boat at sea, no hull slamming, and fairly good fuel economy given size of the boat.
At about 28 knots the 6.2's drink 60LPH combined according to the smartcraft monitors, if you go much beyond that they really get thirsty, at full throttle it gets as high as 190LPH running anything up to 45 knots, but that's just silly fast, it's most comfortable at around 28-36 knots.

As for the Riv and Mustang, I would discount the Riv simply because I find them over rated, Mustangs seem to be beautiful boats but with their extra beam I dare to say they would cost more $$$ in fuel to push them along.
I can't say I have ever heard anyone talk ill of Mustangs other than salesmen of competing brands trying to sell their own brand.
Also with the Mustang because there are so many of them about, there is quite a large Mustang boat club, I think they are based in Brisbane.

[FraidNot]

thanks indeed.
Interesting fuel data. All the other reports I have on the twin 6.2 is a fuel flow of 60 litres PER engine at 22kts. The seatrail charts seem to support this - with the diesel options bringing this back to 70 - 80 lt combined at 22.

[JJB]

It might well be more than the monitors report but there is no way it's 60L per engine.

[FraidNot]

my data is from guys who have done runs and then recorded how many litres needed to fill tanks back to full.
Several sources showing 90 to 110L/h for 6.2L at optimal rpm (3800 if I recall). You may have a very slick beast there

[JJB]

Another thing that can make a difference, what drives were their boats using, Bravo 2's or 3's? We use Bravo 3's, I have heard from a number of people that the B3 drive does make quite a difference to economy, but I still doubt that would make up for the discrepancy between the economy we get to the info you are getting. As I remember back to our purchase the 3700's all came with B2's unless otherwise specified at the point of order.

The B3's will also keep the boat planing at lower speeds and RPM's.

[FraidNot]

thanks for all the advice - very handy indeed!
Do you think the duoprop for Volvo would offer similar performance and ecenomy benefits as the Bravo 3 ?

[JJB]

Originally Posted by FraidNot

thanks for all the advice - very handy indeed!
Do you think the duoprop for Volvo would offer similar performance and ecenomy benefits as the Bravo 3 ?

If anything the Volvo's would likley be a little better than the B3's. If I had to repower the Sunrunner it would be with Volvo rather than Merc.

[FraidNot]

this has all been a great help thanks

[Biggusstickus]

I recently bought a Mustang 3800 and whilst this is an old thread it would have helped me if I had known fairly accurate consumption figures. Therefore to update it the figures I am getting from the 2 x 300hp Mercruisers are 3200 Rpm cruising at 17knots and approx 60lph (both motors) fuel usage.

Would love to hear from others what results they are getting.

[madforboats]

I've got an M430 Mariner (by Riviera) aka Excalibur 47.
we run twin 300 Volvo diesels typically at 3000-3200 RPM getting 22-24kts.
Have recorded fuel usage over a pretty long time and we end up consistently at about 30ltrs/hr for both engines. VERY happy with that having come from thirsty Mercruisers in the last sucking the life out of the credit cards. Anyone heard of the band "Thirsty Merc" - I think they were referring to a marine engine maker not a car maker!

[Biggusstickus]

Originally Posted by madforboats

I've got an M430 Mariner (by Riviera) aka Excalibur 47.
we run twin 300 Volvo diesels typically at 3000-3200 RPM getting 22-24kts.
Have recorded fuel usage over a pretty long time and we end up consistently at about 30ltrs/hr for both engines. VERY happy with that having come from thirsty Mercruisers in the last sucking the life out of the credit cards. Anyone heard of the band "Thirsty Merc" - I think they were referring to a marine engine maker not a car maker!

Alas it would be nice to have the Diesel motors but the budget did not allow the many thousands extra. And at the time of purchase there were none around either. Thats great economy your getting there madforboats.

[andyo56]

Hi all... I'm tossing up between buying a Mustang 3800 or a Sunrunner 3700.
Any thoughts on the pro's and cons of each would be much appreciated.
Interesting theories on the fuel consumption issue. Are there any more ideas?
It seems that most Sunrunners have the 5.7 Mercruisers fitted.
Thanks for any advice. Cheers