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Engine

Posted: Wed Nov 28, 2012 3:43 am
by pirata
Dear Balladers,
My very old MD6A is about to die and I have the possibility to purchase a Yanmar 3gm20 second hand for a very low price.
Do you have any experience with this engine? He fit inside de Ballad? Can I use the same shaft, exsaust, etc
Many thanks and fair winds,
Miguel

Re: Engine

Posted: Wed Nov 28, 2012 4:50 am
by prjacobs
Hi Miguel,
The 3GM20 is a three cylinder engine, which might be a bit of a squeeze to fit the Ballad. I Googled "3GM20" and came up with some specs:

=======================================================================================================
GM/HM Introduced 1980-81, completely new generation of engines. Lighter, smaller, smoother,
Series Quieter. F=Factory Fresh Water, 35-amp alternator, Yanmar mounts.
Model HP Notes Year
1GM 7.5 Raw Water 1980 - 83
2GM(F) 15 Raw or Fresh 1980 - 83
3GM(F) 22.5 Raw or Fresh 1980 - 83
3HM(F) 30 Raw or Fresh 1980 - 83

GM/HM Same models as above except 13-20% more cubic inches and uprated HP. All models
Series except 1GM10 receive 55-amp charging.
Model HP Notes Year
1GM 10 9 Raw Water 1983 - 2009
2GM20(F) 18 Raw or Fresh 1983 - December 2005
3GM30(F) 27 Raw or Fresh 1983 - December 2005
===========================================================================================================

The earlier models appear to be 22.5 hp and the later ones 30 hp.
I have a 2GM20F in #1085. Having never had the boat in the water I can't comment on how it performs yet, although I expect it to be just fine. It's a 2-cylinder engine and there's 23 cm between the end of the shaft tube and the transmission flange, which only leaves 9 cm between the back of the coupling and the front of the Volvo shaft seal. The engine sits as far forward as the engine box allows. If you can get a fresh water cooled model (GMF) you'll have a better, longer lasting engine.

Hope this helps,
Peter.
Image

Re: Engine

Posted: Thu Nov 29, 2012 11:18 pm
by pirata
Many thanks,
I'll check all the measurements of this engine before start the instalation!

Re: Engine

Posted: Mon May 05, 2014 8:38 pm
by pirata
The 3gm was sold and I'm still looking for a new (second hand) engine. I saw a md7b 17hp wich fit exactly in the same mounts of my old md6a. The other one is a 2002 with 18hp. Both engines equiped the latest series of Ballads so I'm sure they are going to fit the engine compartment. But, I noticed that the 2002 is some cm larger in the mounts.. If you have an opinion about these engines I would appreciate to hear it. And the exact proppeler size for these engines. Folding ones are a little expensive so I'm also considering to install a traditional fixed 2 blade.
Many thanks,
Miguel