timing marks?

[galaxy]

I've got a 77' 165 mercruiser and the timing markings are rusty. I don't have a manual so I'm not sure where 8* degrees btdc would be. I'm guessing that zero would be in the center and each mark advances 2 degrees. "Before" being to the left of center and "After" being to the right of center. I'm not sure if this is correct or not for this model and engine. Thanks.

 

[horndog]

Re: timing marks?

BTDC is to the left or starboard side of the marks, or towards the top.. AFTDC is towards the bottom of the hull, or that's where it is pointing. <br /><br />Major marks on it would be up to 12 degrees either direction with 0 being in the dead middle. <br /><br />If it doesn't run right when its pointing to the correct timing, more than likely someone screwed around with it and you will need to find TDC the hard way, then set the distributor to that, then set the timing.

 

[galaxy]

Re: timing marks?

I've actually got the thing running pretty well at the present time. Boat has set for about 8 or 9 years. I just wanted to make sure I set it on 8 degrees and not twelve. Can't make out any indentions on the tab. Can only go by the tooth points. Thanks