It's a secondary fuel. Cng or propane. Just google propane injection. It's not free power but cng is cheap, clean and a pretty decent power adder. Kits are pretty reasonable and a pretty safe way to do it

http://http://www.dieselperformanceproducts.com/faq.html

hey there...l thanks for keeping the post goin....but here what my research has done for me.....
I found that not too much ppl are running diesels except for sports fisherman, work boats, etc...
hmmm.... heard seateks were garbage... no one runs them. no one will service them... and well. u kno the story... out of the pic... duramax...na... looking for that straight marine diesel...
and your take on the whole situation??

They weigh too much for a speed boat, spin too slow to make power and have a useable rpm range, and they cost too much. The fuel economy still can be awesome in spite of those issues though.

nice,,... i looked at fpt... ... and that looks like its out the question...

Too slow....? 90mph+....

https://www.facebook.com/MarathonRacing?ref=bookmarks

why? check out 7075T6's boat

Weight is 1700 lbs with gearbox a 1075 merc is 1300lbs so yes they are heavier but more reliable, parts granted are expensive and hard to come by.

Speed wise I was in a 46 Skater with two of these the boat cruised at 90mph @ 2400 rpm and maxed out out at 110mph at 3100 prm.

The 9lt models are garbage as these were the first models to market, the 10.3lt are much better.