VM/ CMD MD706LX 320hp

Hi Guys

Anyone knows this engine? its in A Sea Ray 390.

I have good experience with Cumins, is this the same thing?

Thanks in advance
Tom

Hi Tom,
I have a pair of these in my princess, they were bought from cummins however they were more commonly sold in uk as cummins mercruiser 4.2L , they have been exceptionally reliable having only let us down once in 10 years. The repair was carried out by cummins under warranty @ 5 years old !
Parts have never been an issue (only ever needed filters, belts and air covers), no tapets to adjust and air filters last for 5 years as they are washable in warm water.
Smoke free and smooth.
Mine are 2004 vintage.
 
Tom,

Sadly more about politics than actual hardware. Feedback from dealers I have had was that the common rail CMD QSD range was exceptionally smooth and quiet and very few problems reported. However there it ends.

With the formation of Cummins Mercruiser the Cummins side was never happy with the VM product however Mercruser tied in with long term supply agreement. From the start Cummins wanted to champion the VW marinised light duty automotive engines.

When the QSD's were launched Cummins were already working with VW Marine as their portfolio offered better strategies for meeting future emissions, in addition VW were willing to work with Cummins to share electronic functionality in order that the Cummins INSITE electronic tooling would work all CMD badged engines VM engines could never be supported with INSITE.

However the big Cummins Mecruiser bust up came over Zeus, Cummins had invested heavily in Zeus and suddenly Mercruser announced that they would be selling the unit to all comers like their out-drives. There are some real sexy electronic algorithms in Zeus which Cummins perceived as giving away the crown jewels.

At the same time Mercruiser dealers in the US were seeing a trend toward diesel engines in their market and were kicking off about all diesel sales being channeled through Cummins dealerships, one also has to remember that many Mercruiser diesel dealers had been Detroit Diesel which was absolute poison.

With the makings of a perfect storm CMD ended with Mercruiser picking up the VW toys and going home and with Cummins Marine back to plowing their own furrow.

The fall out from the end of CMD was that the QSD's ended up as a bit of an orphan, launched by CMD, never embraced 100% by Cummins and with the break up Barrus supporting a range of products that they had no part in launching.

I had a call just two weeks ago from somebody who owned a QSD 2 litre motor which had run like a jem for three years. Non start which should have been a simple fix however QSD had the 9 pin Deutch diagnostic connector used by Cummins. INSITE will not work with this engine and generic diagnostic tool was tried however pin outs on the Deutch connector appear to be different. I suggested that owner contact Barrus for a solution.

DAKA has I believe earlier iteration of VM engine with quasi electronic controls supported by the Mercruiser RINDA tool so no problem.

Marine engines are all about support, however good any engines a couple of spoiled weekends or a ruined holiday is never forgotten.
 
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