I’m wanting to change my impeller on my 502 mag mpi, looks like a straight forward job apart from the top bolt of the bracket looks like it will be obstructed by the circulation pump inlet? Do I need to remove the circulation pump or is there I way around it? I’ve searched but come up with nothing.
cheers

On my 1998 (serpentine belt) 502, I remove the nuts holding the pump to the bracket, then loosen the bracket to create some slack. I then drop the pump off the bracket to work with the hoses. Reassemble in reverse. It's helpful to use a lubricant on the hoses in order to make removal easier (especially the wire-reinforced inlet hose).

It really depends on what year engine you have. On my 2000 502 mpi's, I just loosen the hose clamps and then remove the bolts holding the sea pump to the bracket. Then just pull the entire sea pump out and install new impeller on a bench. Re install in reverse order. It is the same for 1998+ https://www.mercruiserparts.com/bam/...31912/4854/150

1997 cool fuel with V belts, I would pull the sea pump pulley and do it the same as above https://www.mercruiserparts.com/bam/.../31910/2336/19

1997 and earlier with VST system and V belts pretty straight forward and same as 1998+ except you need to disconnect and reconnect fuel pump line. You should also change the gear lube inside it. https://www.mercruiserparts.com/bam/.../31910/2336/18

No reason you should need to remove the bracket on any of them unless its too hard to get to the sea pump to do one of the above.

By the looks of it I have a 97 with cool fuel and belts. The bolts on the pulley are all wired up, does that matter? Remove the wire bolts and pulley and refit the same?

You talking safety wire (as bolts heads have holes in them for the wire) or something else?

Yeah they have safety wire in, not sure why? Sure others I have seen haven’t had safety wire?

Offshore boats may want that due to all the hard impacts and vibration from waves. Its not a bad thing, but is normally not necessary and could be bolted without wire

96 502 Mag, do it in place so as to not mess with the fuel pump. Remove impeller housing only.

it’s a cool fuel model without, so nothing on the raw water pump.