Originally Posted by Florence
Barnakiel, thanks for the info. Can you tell me how they were unreliable? Is it a parts failure issue, more rigorous maintenance requirements or a design issue? Would definitely get a mechanic to check them out.
IMHO problems may stem from design flaws. MD 2xxx series got blocks from a completely different source than their previous models. Many issues related to the cooling system. Below I give you some examples of how they failed:
- back in 2003 we met a boat with engine issues, we made sure the engine had air, fuel
, injectors were fine, compression
was fine, battery
was fine; the engine refused to start, it was then a 'nearly new' unit,
- my neighbour's boat (I believe type MD2003): engine overheated and the mechanic changed parts, cleaned the elbow
, etc, too bad when putting the elbow back, he did not place the gasket
well, small leak from the elbow and a piston ring corroded and seized (look at how the elbow attaches to the manifold and there is no more questions about design flaws, I think, http://www.manuals.zoomshare.com/10....XYOY/image.jpg
- another engine, around 2005, in NZ: overheated, we cleaned the whole kit, checked the thermo, checked the impeller, still overheated,
- my neighbour on the other side: transmission
locked in reverse, saildrive
unit, impossible to fix without removing the transmission
, impossible to remove the transmission due to space limitations, I have seen this kind of transmission failure at least 3 times by now - locks in either reverse or forward,.
All the above were small 2xxx series.
I have had D-2 55 twice and they were great engines, I have MD7 in my boat and I know the pre- 2xxx series pretty well - all good engines, reliable and repairable. I have seen the newest small engine (I think post-2009 or thereabouts) and they seem to be re-designed in many ways.
I think these engines if kept in perfect conditions and current
maintenance done on the regular basis, can be fine engines. Alas, very, very many boat owners have no clue and many boats develop engine problems sooner or later.