timing marks missing-what do i do?

eaboatnuts76

Recruit
Joined
Aug 3, 2005
Messages
1
i got an engine with the timing mark missing in the cranks gear, what would anyone recommend me to do?,I am broke and trying to put back my 79 mercruiser 140 hp motor before season is over!
 

thunderroad

Chief Petty Officer
Joined
Jun 19, 2005
Messages
417
Re: timing marks missing-what do i do?

Maybe a picture in a manual would show where it is in relation to the key slot.<br />or maybe not...
 

steve n carol

Chief Petty Officer
Joined
May 8, 2004
Messages
459
Re: timing marks missing-what do i do?

Yeah, I,m with thunderroad on this, besides 'static' timing, are there timing marks on the flywheel?...sl
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: timing marks missing-what do i do?

exactly what mark is missing? the marks on the crank and cam gear? or the tab on the timing gear cover? ya gotta be specific to get a specific answer. the timing mark on the 140 is a small notch on the balancer rim I belive and the tab has the TDC and BTDC and ATDC marks. in a pinch for ign timing use a dial indicator to locate TDC for #1 and make your own marks. the math is simple once you mark the TDC of #1. if its the mark on the crank to cam gear the gear may be on backwards.
 

Yepblaze

Lieutenant Commander
Joined
Jun 1, 2001
Messages
1,686
Re: timing marks missing-what do i do?

Roll the motor back and forth while probing the spark plug hole to find TDC.<br /><br />Take a dab of white paint and mark the pully and something right next to it.<br /><br />Start it up and use an "advance" timing light.
 

Buttanic

Senior Chief Petty Officer
Joined
Sep 25, 2003
Messages
711
Re: timing marks missing-what do i do?

Rolling the engine and probing the spark plug hole will not find TDC accurately enough to set timing. A degree wheel and positive piston stop is required to find the correct TDC.
 
Top