What about a Rodman 940 twin D4s?

[gordmac]

On my search for a replacement boat. Anyone got an opinion on the above? Anything to look out for with the D4 225hp engines, particularly with highish hours? Boat is on shafts, I am sort of assuming twins on shafts will cost about the same to service as a single on outdrive but less risk of expensive issues?

 

[CLB]

I am sort of assuming twins on shafts will cost about the same to service as a single on outdrive but less risk of expensive issues?

That is true to some extent, in as much as servicing a drive is like servicing an engine. What it doesn't account for though is cutlass bearing replacement and the possibility that your inboard gearbox will also suffer expensive issues. It doesn't happen as often as with a sterndrive, but it is not completely unknown. In short, shaft drive simple, sterndrive more complex.

The big difference between your two options above though, is fuel. Assuming planing speeds and diesel in boath cases: Twin shaft somewhere around 1.5 nmpg. Single sterndrive somewhere around 4 to 5 nmpg.

 

[gordmac]

Thanks.
There is a big difference in fuel consumption, not sure it is as much as you suggest though. From what I have been looking at a single outdrive boat about 1.5l/m, twin shafts about 2.2l/m, lower speed with shafts. Any of the outdrive boats I fancy are a lot more expensive to buy though!

 

[oldgit]

There is a big difference in fuel consumption

Without being contentious
Had both outdrive and shaft drive boats , sold a Princess 33 with outdrives and bought a Broom 37 on shafts.
Both boats had similar sized engines 2 x 130HP and if anything the Broom would have been heavier.
Owned both boats for around 5 years and kept a detailed log of all fuel consumed over that period. Averaged around 100-150 hours per annum.
Boats were both used for non -tidal and coastal cruising with a trip across Le Manche.
The fuel consumption difference was minimal.
The claimed savings on fuel regards outdrives always appeared to be based on high speed consumption, at lower speeds ie. displacement, difference proved to be very small.
How many times is a boat at WOT from the second it leaves the mooring until return.
With increasing fuel costs suspect that careful consideration to opening those throttles will be the norm , giving even less incentive to blast around and reducing the so called fuel advantage of outdrives.

 

[TRH]

Good choice of boat but I would go for a single engine on shaft. With twin engines you will have the expense twice on all things.The one thing you must have if your like me you worry about a breakdown is to carry and outboard.

 

[gordmac]

Thanks for replying.
With only two 130hp engines on that size of boat you would never "get over the hump", I suspect at speeds between hull and planing a planing design will be worse. I suspect you really need to be doing proper hull speed, which is normally lower than you think, or proper on the plane. Just a kn or two over hull speed will kill fuel economy.
I do tend to potter about locally but if I am going somewhere I like to get there without taking forever.
I have had both single and twin shaft boats, I do like the manoeuvrability of twins. My logic is that twin shafts won't cost more to look after than a single outdrive. There are advantages to singles, space round the engine for instance, but with scarce secondhand boats you don't get a lot of choice!

 

[oldgit]

Thanks for replying.
With only two 130hp engines on that size of boat you would never "get over the hump", I suspect at speeds between hull and planing a planing design will be worse. I suspect you really need to be doing proper hull speed, which is normally lower than you think, or proper on the plane. Just a kn or two over hull speed will kill fuel economy.
I do tend to potter about locally but if I am going somewhere I like to get there without taking forever.
I have had both single and twin shaft boats, I do like the manoeuvrability of twins. My logic is that twin shafts won't cost more to look after than a single outdrive. There are advantages to singles, space round the engine for instance, but with scarce secondhand boats you don't get a lot of choice!

Yup about 16/ 17 knots flat out.