Thread: Harmonic balancer on 454 has 4 timing marks.....

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First I guess I should mention my motor knowledge is 5 of 10....at best.

Recently I was forced to replaced a blown 454 in my boat. Due to limited funds I bought a complete, but used marine 454 off a local reputable marine dealer.

The motor that came out was a carburated 1993 stock 454(think Mark IV). Regardless the dealer matched with similar carburated 454.

The new motor is more extreme though: Mid level cam. High rise intake manifold. Merlin heads and a built bottom end. I also upgraded the 650 Holley, with a rebuilt 850 marine Holley.

The new motor starts and runs, but it's a chore.

In order to start. I have to mat the throttle(or pump 20 times). Once running the motor does rev. Of course the boat is out of the water and free of load. I can get to rough idle around 1200rpm(after warming up).

I've adjusted carb every which way. Not much difference. I've checked fuel pressure, sits about 5-1/2 psi. Vacuum at base plate of carb is low(fairly steady 10 inches at 1200 idle).

So to my big problem. Cant really check the timing. The harmonic balancer has 4 marks. Not sure which one is TDC. That's where I could use some help(of course any other suggestions would be great).

As for the four timing marks. One long line(the one the installer set to TDC). An then 3 shorter lines about 5 degrees apart(middle line is longer than two outside lines). These three lines sit maybe thirty degrees before the long line. Making them above TDC, since the long line is TDC.

I verified the long line to be TDC by lining up with the timing tab and pulling the dist. The button was on #1 with the long line on TDC. I also made sure the motor wasnt 180 out by using the finger test.

I assume the installer should have set TDC to the middle of the three marks. I just don't wanna chance changing without some knowledge. I searched all over the internet and couldnt find anything in regards to more than one timing mark.

Thanks for ANY advice! Chris