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Timing marks

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I have a 1997 Mercruiser 7.4 and the timing marks are unlike anything I've seen before. There is an etched line in the crank and a single "V" shaped plate that appears to be the timing guide but there are no other markings on this. The crank is pretty rusty but there appears to be a possible guide just before the etched line on the crank. Does anyone have a photo of this set up and some words of wisdom as to how to time this. I've hooked up the timing light but was not able to determine where the marks are, other than the single etched line in the crank.
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This thread has the pictures and explanation of which marks are what.

http://www.speedwake.com/upload/showthread.php?s=&threadid=56002


The 7.4 may or may not have the marks on the balancer.

If your 7.4 is an EFI/computer controlled motor, you need to put it into service mode, which requires either a scan tool, or a Merc jumper switch. You can also jump the correct 2 wires, but off the top of my head, I can't remember which 2 it is.
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Originally posted by oldsman1728 I have a 1997 Mercruiser 7.4 and the timing marks are unlike anything I've seen before.Â_ There is an etched line in the crank and a single "V" shaped plate that appears to be the timing guide but there are no other markings on this.Â_ The crank is pretty rusty but there appears to be a possible guide just before the etched line on the crank.Â_ Does anyone have a photo of this set up and some words of wisdom as to how to time this.Â_ I've hooked up the timing light but was not able to determine where the marks are, other than the single etched line in the crank.
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I use what I call and "advance" timing light(the one with the dial on the back), just set it to what your base timing is supposed to be and shoot it at zero on the damper, it is also helpfull for checking total advance, set at what you want total, hold the trigger and have someone hit the throttle, when it pulses the light you have it
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5325user said:
This thread has the pictures and explanation of which marks are what.

http://www.speedwake.com/upload/showthread.php?s=&threadid=56002


The 7.4 may or may not have the marks on the balancer.

If your 7.4 is an EFI/computer controlled motor, you need to put it into service mode, which requires either a scan tool, or a Merc jumper switch. You can also jump the correct 2 wires, but off the top of my head, I can't remember which 2 it is.
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Jump A and B on the plug for service mode.

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Thanks for the great advice. Once in service mode, do I then set to the required specs per the manual (I believe it is 10 BTDC for my engine)? Does the service mode take away any engine advance?

I assume I can then use either regular timing light and the marks on the balancer or TDC with an advance timing light - will either work?
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oldsman1728 said:
Thanks for the great advice. Once in service mode, do I then set to the required specs per the manual (I believe it is 10 BTDC for my engine)? Does the service mode take away any engine advance?

I assume I can then use either regular timing light and the marks on the balancer or TDC with an advance timing light - will either work?
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yes, once in service mode, set the base timing. Any regular timing light is fine.
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