Yanmars are nice motors from what I've seen. Can they bump the HP up on them? What type of HP do you get?

I don`t think that bravos are going to like all that torque.

How about #6's???

how about shaft drives....

konrads will take it no problem.

Don't think about offroad fuel in a Duramax unless you have access to a bottomless source of replacement fuel injectors or a MUCH improved fuel filtration system. The Bosch systems have no tolerance for dirty fuel.

Yanmar already makes 550's in a reasonable size/weight package. There was a story a while back in one of the mags where one of Yanmar's largest repower dealers in South Florida put a pair of 550's in a 36' Spectre. Had to run like a 1.11 gear in the outdrives and a 36" wheel due to the low RPM but they did get 108mph out of it. I know the outdrives wouldn't stand up to that incredible torque for long but 6's or Konrad's would do the trick. And, as was stated before, as long as you keep the fuel/water separator clean, buy fuel from a reputable station and keep the oil changed, the oil burners will last a LONG, LONG time.

the marine ones have a totally different fuel system.... inculding a complex fuel de-aerating system to get all the air out... it will be impressive when it debuts...

the boat they are going into already has shaft drives.... remember we are talking about 1400 HP froma diesel so torque will be in the 2k range....

CCPerformance-
Dirty fuel is a problem for all diesels- Died fuel no problem.
That is and old BS story the dealers like to propagate. The died fuel is actually made at the local distributor with an additive very similar to ATF which truckers have been adding for 30 years. Simply a little more detergent. I have 12 Duramax trucks that have ran their entire ives with died fuel- some dealers gig the customer on warrenty claims by asking about if they have used died fuels- then they charge for flush, etc. I have hundreds of farmer friends- I am a contractor We have all fought the BS battle and have won easily.