[QUOTE=ADI;375490] I've worked on loads of V6 Merc / Mariners and it 's usually ( if your sure the battery's ok) the battery leads or the starter motor's not turning the engine over fast enough to start when cold.
When cold they fire up then cut out and so on. You need a good cranking starter to get them to fire from cold.
Is the starter motor the original ? [/QUO
Hi ADI tx for your comment. Batts still charging full now have then home and have just finished a three phase charge and there both over 13vlts. The battery leads were renewed 2 years ago from bats to engine. If you have looked at the thread from start you will have gathered that we have talked about the starter!! I never think it is ok and I am going to get it stripped down over the winter. Yes it is the original do you think it is due a new one?
Where abouts are you in Scotland/