470 Timing Marks

A

Adiredneck

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I have a 1987 Mercruiser 470 3.7L

The marks on the timing cover . . There is a larger range on one side of 0 degrees (left side of cover) and shorter on the right side of 0.

Is the longer range on the left before or after? TDC

:confused:
 
Bondo

Bondo

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Re: 470 Timing Marks

Adiredneck said:
I have a 1987 Mercruiser 470 3.7L

The marks on the timing cover . . There is a larger range on one side of 0 degrees (left side of cover) and shorter on the right side of 0.

Is the longer range on the left before or after? TDC

:confused:
Click to expand...

Ayuh,.... Welcome Aboard,.... Where about's in the dack's,..?? I've got a place just outside the blue line in Lewis County,....

The longer range is Btc, the shorter is after,....
 
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Adiredneck

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Re: 470 Timing Marks

Bondo said:
Ayuh,.... Welcome Aboard,.... Where about's in the dack's,..?? I've got a place just outside the blue line in Lewis County,....

The longer range is Btc, the shorter is after,....
Click to expand...

Near Schroon. Bought first boat in May, took 2 years to convince wife that it was a good idea. Only able to take it out 4x this summer 'cause so much broke on it. Broke down on the lake 2 of the 4 times we went out, now I am in serious jeopardy with the wife for wasting about 6 complete weekends fixing. Boat was having the classic flood/stall/die after warming up on the lake. always popped out the carb on fast accel. Just cleaned tank out, new fuel, fuel line, fuel filter, cap rotor, (points are electronic), plugs, and rebuilt the carb. Timing is set with the light 5 degrees to the right of the mark which I thought was BTDC, but looks like I am wrong. boat idles worse when I move timing to the left of the 0 degree mark, but I will try again now that I have rebuilt carb. Carb after rebuild no longer drips from the venturis, and I see many posts that claim carb pop is due to lean mix so I will try unscrewing the mixture screw 1/2 turn at a time on the Mercarb 2bbl. Getting a little discouraged.
 
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stonyloam

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Re: 470 Timing Marks

Here is your engine manual: Boatinfo - Mercruiser Service Manual nr. 8 - 1985-1989 - Mercury Marine 4 Cylinder Engines Remember your distributor rotor rotates clockwise, so to advance the timing turn the distributor counterclockwise. As with all 470's you should do a compression check and cooling system pressure check just to determine your overall engine health (borrow the tools from Autozone). One other thing check the little weep hole on the lower starboard side of the timing cover (engine water pump), to make sure it is clear and open, and that it is not leaking coolant when the engine is running. It is best to refer to starboard and port rather than right and left. Starboard is right looking from the stern forward, so the starboard side of your engine is always starboard no matter which way you are looking at it.
 
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Adiredneck

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Re: 470 Timing Marks

Thank you, new best friend :), will do.

The dash gauge for coolant temp never climbs above 120F. I am going to get an infrared thermo and double check it. I have the gaskets and seals to replace the water pump seals. I am sorta forced to do it because the WP cover is cracked due to previous owner retrofitting to an alternator charging system and using one of the WP cover bolts as the main mount for the alternator. cracked the cover. Was it einstein that said that the difference between genius and stupidity is that genuis has its limits.

I will replace water pump seals, clean out heat exchanger & seals, new thermostat (160F) and do the coolant pressure test and compression.
 
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