310 engine ground

May 10, 2012
14
Catalina 310 Bayport
Where is the engine ground on the C310 M25XPB.
Appreciate anyone that can point me in the right direction.
Photo or diagram appreciated. Have read more than a few threads on electrical issues on 310's....sounds like the engine ground is a good place to start.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
On our C310, hull #31, it was a bell housing bolt. Pretty sure it was an M8, but a 1/2” hex wrench fit it. I used a 5/16” lug to connect the new cable. It was a real bear to get at.
 
Apr 17, 2013
153
Catalina 310 57 Pompano Beach, FL
We have hull #57 the ground is attached to the lifting eye for the engine. Will send a picture tomorrow.
 

leo310

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Dec 15, 2006
635
Catalina 310 44 Campbell River BC
The cable is attached to the starter bolt, but then I have a yanmar.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Any chance this is it for the Universal M25. Green wire on port side of engine. (Not my engine, I wish my mounts were that good!).
That’s probably a ground, but you’d have to trace where it goes. Very possible that each C310 is slightly different.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Any chance this is it for the Universal M25. Green wire on port side of engine. (Not my engine, I wish my mounts were that good!).
This pic is one of my boat. If you go behind the oil pressure switch you can find a bolt with stacked lugs. This is the primary source on for bad grounds on our boats. Put a buss bar in instead. I have to run to work now, so let me know if you have any questions.
 
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