Fordiesel69 232 #1 Posted September 20, 2013 I was wondering aside from pulling the head, is there a way to tell if a M12 or M14 has a style D mahle, or style A. Just curious. Share this post Link to post Share on other sites
Fordiesel69 232 #3 Posted October 5, 2013 The suspense killed me. Yanked the M12 head off last night to decarbon at 534hrs. Glad I did as it has the style D. Will do the M14 today at 253hrs as all it did was plow snow during the winter. Share this post Link to post Share on other sites
leeave96 487 #4 Posted October 9, 2013 How do you know the style as you look at it and what are the advantages? I've got a 14hp Kohler magnum and one of these days I'll pull the head to decarbon and this would be interesting info to know. Thanks! Bill Share this post Link to post Share on other sites
Fordiesel69 232 #5 Posted October 10, 2013 The style "A" piston is just a regular small engine piston that kohler has been using for a very long time. There is nothing wrong with it per say, but it is just old school. The skirt is quite large so in a high hour engine the cylinder bore will be quite oval what it wears. The style "D" piston is a MAHLE brand piston, and has a much improved wrist pin area (stronger) and much better rings. They are thinner and apply more direct pressure for better oil control. These pistons tend to not wear the cylinders as much per my research as it is overall shorter which means less metal contact. I have not owned a 2500+ hour style "D" engine to confirm for myself but the general opinion is they are far better. The way you can tell on your engine is after the carbon is cleaned off, you will see an arrow with the word FLY pointing towards the flywheel if style D. The style A will have no marks in terms of direction. Style A: Style D: Share this post Link to post Share on other sites
leeave96 487 #6 Posted October 11, 2013 The style "A" piston is just a regular small engine piston that kohler has been using for a very long time. There is nothing wrong with it per say, but it is just old school. The skirt is quite large so in a high hour engine the cylinder bore will be quite oval what it wears. The style "D" piston is a MAHLE brand piston, and has a much improved wrist pin area (stronger) and much better rings. They are thinner and apply more direct pressure for better oil control. These pistons tend to not wear the cylinders as much per my research as it is overall shorter which means less metal contact. I have not owned a 2500+ hour style "D" engine to confirm for myself but the general opinion is they are far better. The way you can tell on your engine is after the carbon is cleaned off, you will see an arrow with the word FLY pointing towards the flywheel if style D. The style A will have no marks in terms of direction. Style A: Style D: Good info. Thanks! Bill Share this post Link to post Share on other sites
