454 Timing procedure...

Friend's boat... 454 "magnum Bravo" Carbed engine S/N 0C462174... third owner boat... replacing Distributor cap ( T'bolt V)..

Am familiar with the setup up and base timing procedure for 5.7L, however this harness looks different. Can't find a "loose" wire to ground.... There is a wire in the harness near the disti that has a very short jumper back to another wire in the same harness.... Is this the wire??... Can't tell the color of wire since there is black overspray paint on the wires.... IFSO, Did I find the motor locked in the "base timing mode" .... or is it pull jumper to set base timing????


TIA

/Bob

What the heck are you doing?

My old 4 cylinder 3.0 required grounding a wire to set the base timing. Not sure that's the case here, however.

Jeff

Based on serial number look up, 1988-1992 454 Plug serial number into search box at top.

https://public-mercurymarine.sysonl...est&NA_KEY=NA_KEY_VALUE&langIF=eng&langDB=eng


It shows a TB V but NO jumper. This appears to be an early TB V which is only a timing module change but still functions basically the same as TB IV including timing procedure.

kghost said:

Based on serial number look up, 1988-1992 454 Plug serial number into search box at top.

https://public-mercurymarine.sysonl...est&NA_KEY=NA_KEY_VALUE&langIF=eng&langDB=eng


It shows a TB V but NO jumper. This appears to be an early TB V which is only a timing module change but still functions basically the same as TB IV including timing procedure.

Click to expand...

Thank you Jack